diff --git a/src/web/js/lib/account_validator.js b/src/web/js/lib/account_validator.js
index d654435..dc276d9 100644
--- a/src/web/js/lib/account_validator.js
+++ b/src/web/js/lib/account_validator.js
@@ -57,14 +57,12 @@ class AccountValidator {
 	}
 
 	messageForInvalidPlayerID(textID) {
-		if(textID.length < AccountValidator.Player_ID_LENGTH_MINIMUM)
-			return "마에스트로 계정명은 " + AccountValidator.Player_ID_LENGTH_MINIMUM + "글자 이상이어야 합니다.";
-		else if(textID.length > AccountValidator.Player_ID_LENGTH_MAXIMUM)
-			return "마에스트로 계정명은 " + AccountValidator.Player_ID_LENGTH_MAXIMUM + "글자 이하이어야 합니다.";
-		else if(!(/^[A-Za-z]/.test(textID)))
-			return "마에스트로 계정명은 알파벳으로 시작해야 합니다.";
-		else if((/[^\w]/g).test(textID))
-			return "마에스트로 계정명은 알파벳과 숫자로만 적어주세요.";
+		if(textID.length < Number(AccountValidator.Player_ID_LENGTH_MINIMUM))
+			return "학생 이름은 " + AccountValidator.Player_ID_LENGTH_MINIMUM + "글자 이상이어야 합니다.";
+		else if(textID.length > Number(AccountValidator.PLAYER_ID_LENGTH_MAXIMUM))
+			return "학생 이름은 " + AccountValidator.PLAYER_ID_LENGTH_MAXIMUM + "글자 이하이어야 합니다.";
+		else // if((/[^A-Za-z0-9가-힣-_]/g).test(textID))
+			return "학생 이름 입력 가능한 문자는 [ 한글, 알파벳, 숫자, -, _ ] 입니다.";
 	}
 
 
@@ -76,15 +74,12 @@ class AccountValidator {
 	}
 
 	messageForInvalidPlayerPW(textPW) {
-		console.log(textPW);
-		if(textPW.length < AccountValidator.Player_PW_LENGTH_MINIMUM)
-			return "마에스트로의 암호는 " + AccountValidator.Player_PW_LENGTH_MINIMUM + "글자 이상이어야 합니다.";
-		else if(textPW.length > AccountValidator.Player_PW_LENGTH_MAXIMUM)
-			return "마에스트로의 암호는 " + AccountValidator.Player_PW_LENGTH_MAXIMUM + "글자 이하이어야 합니다.";
-		else if((/[^\w]/g).test(textPW))
-			return "마에스트로의 암호는 알파벳과 숫자로만 적어주세요.";
+		if(textPW.length < Number(AccountValidator.PLAYER_PW_LENGTH_MINIMUM))
+			return "학생 입장 번호는 " + AccountValidator.PLAYER_PW_LENGTH_MINIMUM + "글자 이상의 숫자로 입력해 주세요.";
+		else if(textPW.length > Number(AccountValidator.PLAYER_PW_LENGTH_MAXIMUM))
+			return "학생 입장 번호는 " + AccountValidator.PLAYER_PW_LENGTH_MAXIMUM + "글자 이하의 숫자로 입력해 주세요.";
 		else
-			return "???";
+			return "학생 입장 번호는 4~6자리 숫자로 입력해 주세요.";
 	}
 
 
diff --git a/src/web/maestro/main_menu.html b/src/web/maestro/main_menu.html
index fe330b3..709cc6e 100644
--- a/src/web/maestro/main_menu.html
+++ b/src/web/maestro/main_menu.html
@@ -11,6 +11,7 @@
 
 	<script type="text/javascript" src="./../../../resources/jquery/jquery-3.3.1.min.js"></script>
 	<script type="text/javascript" src="./../js/main.js"></script>
+	<script type="text/javascript" src="./../js/lib/account_validator.js"></script>
 	<script type="text/javascript" src="./../js/request_server.js"></script>
 	<script type="text/javascript" src="./../js/maestro_main.js"></script>
 	<script type="text/javascript" src="./../js/player_list.js"></script>
diff --git a/src/web/module/maestro_section_add_player.html b/src/web/module/maestro_section_add_player.html
index 3af56b4..24b6018 100644
--- a/src/web/module/maestro_section_add_player.html
+++ b/src/web/module/maestro_section_add_player.html
@@ -1,5 +1,7 @@
 <script type="text/javascript">
 
+let accountValidator = new AccountValidator();
+
 $(document).ready(function() {
 	addPlayerListManager = new PlayerListManager(
 		$("#add_player_list"),
@@ -13,6 +15,17 @@ function addPlayer() {
 	let playerName = $("#add_player_name").val();
 	let enterCode = $("#add_player_enter_code").val();
 
+	if(!accountValidator.isValidPlayerID(playerName)) {
+		console.log("Error - playerName : " + playerName);
+		onErrorPlayerID(accountValidator.messageForInvalidPlayerID(playerName));
+		return;
+	} else if(!accountValidator.isValidPlayerPW(enterCode)) {
+		console.log("Error - enterCode : " + enterCode);
+		onErrorPlayerPW(accountValidator.messageForInvalidPlayerPW(enterCode));
+		return;
+	}
+
+	/*
 	if(playerName.length === 0) {
 		// $("#add_player_notice").val("학생 이름을 입력하세요.");
 		$("#error_message").text("학생 이름을 입력하세요.");
@@ -24,6 +37,7 @@ function addPlayer() {
 		$("#add_player_enter_code").focus();
 		return;
 	}
+	*/
 
 	sendRequestServer(	//url, sendParams, onSuccess, onFail, isDebugMode);
 		"./../server/player/add_player.php",
@@ -42,6 +56,25 @@ function addPlayer() {
 	);
 }
 
+function onErrorPlayerID(message) {
+	if($("#error_message").length) {
+		$("#error_message").text(message);
+	}
+
+	$("#maestro_name").val("");
+	$("#maestro_name").focus();
+}
+
+function onErrorPlayerPW(message) {
+	if($("#error_message").length) {
+		$("#error_message").text(message);
+	}
+
+	$("#password").val("");
+	$("#password").focus();
+}
+
+
 </script>
 
 
diff --git a/src/web/module/maestro_section_register.html b/src/web/module/maestro_section_register.html
index 163629b..632ac94 100644
--- a/src/web/module/maestro_section_register.html
+++ b/src/web/module/maestro_section_register.html
@@ -27,7 +27,7 @@
 
 <script type="text/javascript">
 
-let maestro_name = "";
+let maestroName = "";
 let isAvailableID = false;
 
 let password = "";
@@ -47,20 +47,20 @@ $(document).ready(function() {
 });
 
 function checkMaestroID() {
-	maestro_name = $("#maestro_name").val();
+	maestroName = $("#maestro_name").val();
 
-	if(!accountValidator.isValidMaestroID(maestro_name)) {
-		onErrorMaestroID(accountValidator.messageForInvalidMaestroID(maestro_name));
+	if(!accountValidator.isValidMaestroID(maestroName)) {
+		onErrorMaestroID(accountValidator.messageForInvalidMaestroID(maestroName));
 		return;
 	}
 
 	sendRequestServer(	//url, sendParams, onSuccess, onFail, isDebugMode);
 		"./../server/maestro/check_id.php",
-		"maestro_name=" + maestro_name,
+		"maestro_name=" + maestroName,
 
 		(jsonData) => {
 			isAvailableID = true;
-			$("#error_message").text(maestro_name + " : 생성 가능한 마에스트로 계정 이름입니다.");
+			$("#error_message").text(maestroName + " : 생성 가능한 마에스트로 계정 이름입니다.");
 		},
 
 		(errorMessage, errorCode) => {
@@ -150,7 +150,7 @@ function register_account() {
 
 	sendRequestServer(	//url, sendParams, onSuccess, onFail, isDebugMode);
 		"./../server/maestro/add_maestro.php",
-		"maestro_name=" + maestro_name + "&password=" + password + "&email=" + email + "&account_type=" + selectedAccountTypeValue,
+		"maestro_name=" + maestroName + "&password=" + password + "&email=" + email + "&account_type=" + selectedAccountTypeValue,
 
 		(jsonData) => {
 			isAvailableID = true;
diff --git a/src/web/module/maestro_section_search.html b/src/web/module/maestro_section_search.html
index 24dea3a..5516be3 100644
--- a/src/web/module/maestro_section_search.html
+++ b/src/web/module/maestro_section_search.html
@@ -5,18 +5,13 @@ $(document).ready(function() {
 		$("#search_player_list"),
 		$("#search_player_list_navigator > #page_no_area")
 	);
-
-	// searchPlayerListManager.setupSearchPlayerList("");
-	console.log("search - ready");
 });
 
 
 function searchPlayer() {
-	// let maestroID = sessionStorage.getItem("maestroID");
 	let playerName = $("#search_name").val();
 
 	if(playerName.length === 0) {
-		// $("#search_name_notice").val("학생 이름을 입력하세요.");
 		$("#search_name").focus();
 		return;
 	}
@@ -34,15 +29,6 @@ function searchPlayer() {
 	<input type="text" id="search_name"><input type="submit" name="찾기" onClick="searchPlayer()"><br/>
 	<br/>
 
-<!--
-	<h3>검색 결과</h3>
-
-	학생 이름
-	<input type="text" id="result_name"><button>삭제</button><br/>
-	입장 코드
-	<input type="text" id="result_entercode"><button>수정</button>
- -->
-
 </span>
 
 <span id="search_result">
diff --git a/src/web/server/player/add_player.php b/src/web/server/player/add_player.php
index 73579e4..1149f31 100644
--- a/src/web/server/player/add_player.php
+++ b/src/web/server/player/add_player.php
@@ -18,30 +18,44 @@ if(!is_numeric($enterCode)) {
 */
 
 
-$result = hasPlayerName($maestroID, $playerName, $enterCode);
+$result = has_player_name($maestroID, $playerName, $enterCode);
 if($result !== null) {
 	set_error_message("이미 등록된 학생과 입장 코드 정보입니다.");
 	send_result_fail();
 	exit;
 }
 
-addPlayer($maestroID, $playerName, $enterCode);
+$maestroAccountType = get_maestro_account_type($maestroID);
+$playerCount = get_player_count($maestroID);
+if($playerCount >= $maestroAccountType * 10) {
+	set_error_message("학생을 더 이상 추가할 수 없습니다. (더 많은 학생수로 업그레이드 하세요)");
+	send_result_fail();
+	exit;
+}
 
-$result = hasPlayerName($maestroID, $playerName, $enterCode);
+add_player($maestroID, $playerName, $enterCode);
+
+$result = has_player_name($maestroID, $playerName, $enterCode);
 if($result === null) {
 	set_error_message("학생 등록에 실패했습니다.");
 	send_result_fail();
 	exit;
 }
 
+increase_player_count($maestroID, 1);
+
 send_result_success();
 exit;
 
 
-function hasPlayerName($maestroID, $playerName, $enterCode) {
+function has_player_name($maestroID, $playerName, $enterCode) {
 	global $db_conn;
 
-	$query = "SELECT PlayerID FROM moty_player WHERE MaestroID=? AND Name=? AND EnterCode=?";
+	$query = "
+		SELECT PlayerID
+		FROM moty_player
+		WHERE MaestroID = ? AND Name = ? AND EnterCode = ?
+	";
 	$stmt = $db_conn->prepare($query);
 	$stmt->bind_param("iss", $maestroID, $playerName, $enterCode);
 	$stmt->execute();
@@ -53,13 +67,67 @@ function hasPlayerName($maestroID, $playerName, $enterCode) {
 	return $playerID;
 }
 
-function addPlayer($maestroID, $playerName, $enterCode) {
+function get_maestro_account_type($maestroID) {
 	global $db_conn;
 
-	$query = "INSERT INTO moty_player (MaestroID, Name, EnterCode) VALUES (?, ?, ?)";
+	$query = "
+		SELECT AccountType
+		FROM moty_maestro
+		WHERE MaestroID = ?
+	";
+	$stmt = $db_conn->prepare($query);
+	$stmt->bind_param("i", $maestroID);
+	$stmt->execute();
+	$stmt->bind_result($accountType);
+	// while($stmt->fetch())
+	$stmt->fetch();
+	$stmt->close();
+
+	return $accountType;
+}
+
+function get_player_count($maestroID) {
+	global $db_conn;
+
+	$query = "
+		SELECT PlayerCount
+		FROM moty_maestro
+		WHERE MaestroID = ?
+	";
+	$stmt = $db_conn->prepare($query);
+	$stmt->bind_param("i", $maestroID);
+	$stmt->execute();
+	$stmt->bind_result($playerCount);
+	// while($stmt->fetch())
+	$stmt->fetch();
+	$stmt->close();
+
+	return $playerCount;
+}
+
+function add_player($maestroID, $playerName, $enterCode) {
+	global $db_conn;
+
+	$query = "
+		INSERT INTO moty_player (MaestroID, Name, EnterCode)
+		VALUES (?, ?, ?)
+	";
 	$stmt = $db_conn->prepare($query);
 	$stmt->bind_param("iss", $maestroID, $playerName, $enterCode);
 	$stmt->execute();
 }
 
+function increase_player_count($maestroID, $count) {
+	global $db_conn;
+
+	$query = "
+		UPDATE moty_maestro
+		SET PlayerCount = PlayerCount + ?
+		WHERE MaestroID = ?
+	";
+	$stmt = $db_conn->prepare($query);
+	$stmt->bind_param("ii", $count, $maestroID);
+	$stmt->execute();
+}
+
 ?>
\ No newline at end of file
diff --git a/src/web/server/player/delete_player.php b/src/web/server/player/delete_player.php
index 04676af..8bac888 100644
--- a/src/web/server/player/delete_player.php
+++ b/src/web/server/player/delete_player.php
@@ -24,6 +24,8 @@ if($result === true) {
 	exit;
 }
 
+decrease_player_count($maestroID, 1);
+
 send_result_success();
 exit;
 
@@ -31,7 +33,10 @@ exit;
 function deletePlayer($maestroID, $playerID) {
 	global $db_conn;
 
-	$query = "DELETE FROM moty_best_record WHERE MaestroID = ? AND PlayerID = ?";
+	$query = "
+		DELETE FROM moty_best_record
+		WHERE MaestroID = ? AND PlayerID = ?
+	";
 	$stmt = $db_conn->prepare($query);
 	$stmt->bind_param("ii", $maestroID, $playerID);
 	$result = $stmt->execute();
@@ -41,7 +46,10 @@ function deletePlayer($maestroID, $playerID) {
 	// 	echo "deleted row count : ".$stmt->affected_rows;
 	// }
 
-	$query = "DELETE FROM moty_player WHERE MaestroID = ? AND PlayerID = ?";
+	$query = "
+		DELETE FROM moty_player
+		WHERE MaestroID = ? AND PlayerID = ?
+	";
 	$stmt = $db_conn->prepare($query);
 	$stmt->bind_param("ii", $maestroID, $playerID);
 	$result = $stmt->execute();
@@ -55,7 +63,11 @@ function deletePlayer($maestroID, $playerID) {
 function hasPlayerID($maestroID, $playerID) {
 	global $db_conn;
 
-	$query = "SELECT PlayerID FROM moty_player WHERE MaestroID=? AND PlayerID=?";
+	$query = "
+		SELECT PlayerID
+		FROM moty_player
+		WHERE MaestroID=? AND PlayerID=?
+	";
 	$stmt = $db_conn->prepare($query);
 	$stmt->bind_param("ii", $maestroID, $playerID);
 	$stmt->execute();
@@ -73,7 +85,11 @@ function hasPlayerID($maestroID, $playerID) {
 function hasPlayerRecord($maestroID, $playerID) {
 	global $db_conn;
 
-	$query = "SELECT PlayerID FROM moty_best_record WHERE MaestroID=? AND PlayerID=?";
+	$query = "
+		SELECT PlayerID
+		FROM moty_best_record
+		WHERE MaestroID=? AND PlayerID=?
+	";
 	$stmt = $db_conn->prepare($query);
 	$stmt->bind_param("ii", $maestroID, $playerID);
 	$stmt->execute();
@@ -88,4 +104,17 @@ function hasPlayerRecord($maestroID, $playerID) {
 	return false;
 }
 
+function decrease_player_count($maestroID, $count) {
+	global $db_conn;
+
+	$query = "
+		UPDATE moty_maestro
+		SET PlayerCount = PlayerCount - ?
+		WHERE MaestroID = ?
+	";
+	$stmt = $db_conn->prepare($query);
+	$stmt->bind_param("ii", $count, $maestroID);
+	$stmt->execute();
+}
+
 ?>
\ No newline at end of file
diff --git a/src/web/sql/make_db.sql b/src/web/sql/make_db.sql
index 189e470..a747541 100644
--- a/src/web/sql/make_db.sql
+++ b/src/web/sql/make_db.sql
@@ -6,7 +6,7 @@ CREATE TABLE moty_maestro (
 	AccountType INT UNSIGNED NOT NULL,
 	ActivateStatus INT UNSIGNED NOT NULL,
 	AvailableActivateDateTime DATETIME NOT NULL,
-	UserCount INT UNSIGNED NOT NULL,
+	PlayerCount INT UNSIGNED NOT NULL,
 	AcceptClausesDateTime DATETIME NOT NULL,
 	MaestroTestID INT UNSIGNED
 );
@@ -52,7 +52,7 @@ CREATE TABLE moty_best_record (
 
 	FOREIGN KEY (MaestroID) REFERENCES moty_maestro(MaestroID),
 	FOREIGN KEY (AppID) REFERENCES moty_app(AppID),
-	FOREIGN KEY (UserID) REFERENCES moty_user(UserID)
+	FOREIGN KEY (PlayerID) REFERENCES moty_player(PlayerID)
 );
 
 CREATE TABLE moty_ranking (
@@ -65,5 +65,5 @@ CREATE TABLE moty_ranking (
 
 	FOREIGN KEY (MaestroID) REFERENCES moty_maestro(MaestroID),
 	FOREIGN KEY (AppID) REFERENCES moty_app(AppID),
-	FOREIGN KEY (UserID) REFERENCES moty_user(UserID)
+	FOREIGN KEY (PlayerID) REFERENCES moty_player(PlayerID)
 );