diff --git a/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java b/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java
index 6bba3f5f04..e5bce2cc74 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/mysql/parser/MySqlStatementParser.java
@@ -2442,23 +2442,43 @@ public class MySqlStatementParser extends SQLStatementParser {
                 stmt.addItem(item);
             } else if (identifierEquals("MODIFY")) {
                 lexer.nextToken();
+                
                 if (lexer.token() == Token.COLUMN) {
                     lexer.nextToken();
                 }
-                MySqlAlterTableModifyColumn item = new MySqlAlterTableModifyColumn();
-                item.setNewColumnDefinition(this.exprParser.parseColumn());
-                if (identifierEquals("AFTER")) {
-                    lexer.nextToken();
-                    item.setAfterColumn(this.exprParser.name());
-                } else if (identifierEquals("FIRST")) {
-                    lexer.nextToken();
-                    if (lexer.token() == Token.IDENTIFIER) {
-                        item.setFirstColumn(this.exprParser.name());
-                    } else {
-                        item.setFirst(true);
-                    }
+                
+                boolean paren = false;
+                if (lexer.token() == Token.LPAREN) {
+                	paren = true;
+                	lexer.nextToken();
+                }
+                
+                for (;;) {
+					MySqlAlterTableModifyColumn item = new MySqlAlterTableModifyColumn();
+					item.setNewColumnDefinition(this.exprParser.parseColumn());
+					if (identifierEquals("AFTER")) {
+						lexer.nextToken();
+						item.setAfterColumn(this.exprParser.name());
+					} else if (identifierEquals("FIRST")) {
+						lexer.nextToken();
+						if (lexer.token() == Token.IDENTIFIER) {
+							item.setFirstColumn(this.exprParser.name());
+						} else {
+							item.setFirst(true);
+						}
+					}
+					stmt.addItem(item);
+					
+					if (paren && lexer.token() == Token.COMMA) {
+						lexer.nextToken();
+						continue;
+					}
+					break;
+                }
+                
+                if (paren) {
+                	accept(Token.RPAREN);
                 }
-                stmt.addItem(item);
             } else if (lexer.token() == Token.DISABLE) {
                 lexer.nextToken();
 
diff --git a/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java b/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java
index 0cce4a8d54..829ddcb2d3 100644
--- a/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java
+++ b/src/main/java/com/alibaba/druid/sql/dialect/mysql/visitor/MySqlOutputVisitor.java
@@ -299,8 +299,12 @@ public class MySqlOutputVisitor extends SQLASTOutputVisitor implements MySqlASTV
 
     public boolean visit(SQLColumnDefinition x) {
         x.getName().accept(this);
-        print(' ');
-        x.getDataType().accept(this);
+        
+        SQLDataType dataType = x.getDataType();
+		if (dataType != null) {
+	        print(' ');
+	        dataType.accept(this);
+        }
 
         if (x.getCharsetExpr() != null) {
             print0(ucase ? " CHARSET " : " charset ");
diff --git a/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest23.java b/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest23.java
new file mode 100644
index 0000000000..7f4fe01622
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest23.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright 1999-2101 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.bvt.sql.mysql;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+import com.alibaba.druid.sql.parser.Token;
+
+public class MySqlAlterTableTest23 extends TestCase {
+
+    public void test_alter_add_key() throws Exception {
+        String sql = "alter table xxxxx modify (xxx default '0');";
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        SQLStatement stmt = parser.parseStatementList().get(0);
+        parser.match(Token.EOF);
+        String output = SQLUtils.toMySqlString(stmt);
+        Assert.assertEquals("ALTER TABLE xxxxx"
+        		+ "\n\tMODIFY COLUMN xxx DEFAULT '0'", output);
+    }
+}
diff --git a/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest24.java b/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest24.java
new file mode 100644
index 0000000000..8c79518831
--- /dev/null
+++ b/src/test/java/com/alibaba/druid/bvt/sql/mysql/MySqlAlterTableTest24.java
@@ -0,0 +1,39 @@
+/*
+ * Copyright 1999-2101 Alibaba Group Holding Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.druid.bvt.sql.mysql;
+
+import junit.framework.TestCase;
+
+import org.junit.Assert;
+
+import com.alibaba.druid.sql.SQLUtils;
+import com.alibaba.druid.sql.ast.SQLStatement;
+import com.alibaba.druid.sql.dialect.mysql.parser.MySqlStatementParser;
+import com.alibaba.druid.sql.parser.Token;
+
+public class MySqlAlterTableTest24 extends TestCase {
+
+    public void test_alter_add_key() throws Exception {
+        String sql = "alter table xxxxx modify (f0 default '0',f1 default '0');";
+        MySqlStatementParser parser = new MySqlStatementParser(sql);
+        SQLStatement stmt = parser.parseStatementList().get(0);
+        parser.match(Token.EOF);
+        String output = SQLUtils.toMySqlString(stmt);
+        Assert.assertEquals("ALTER TABLE xxxxx"
+        		+ "\n\tMODIFY COLUMN f0 DEFAULT '0',"
+        		+ "\n\tMODIFY COLUMN f1 DEFAULT '0'", output);
+    }
+}