diff --git a/ast/ddl.go b/ast/ddl.go
index 1debb12be5..3651c8848c 100644
--- a/ast/ddl.go
+++ b/ast/ddl.go
@@ -646,6 +646,18 @@ const (
 // TODO: Add more actions
 )
 
+// LockType is the type for AlterTableSpec.
+// See https://dev.mysql.com/doc/refman/5.7/en/alter-table.html#alter-table-concurrency
+type LockType byte
+
+// Lock Types.
+const (
+	LockTypeNone LockType = iota + 1
+	LockTypeDefault
+	LockTypeShared
+	LockTypeExclusive
+)
+
 // AlterTableSpec represents alter table specification.
 type AlterTableSpec struct {
 	node
@@ -658,6 +670,7 @@ type AlterTableSpec struct {
 	NewColumn     *ColumnDef
 	OldColumnName *ColumnName
 	Position      *ColumnPosition
+	LockType      LockType
 }
 
 // Accept implements Node Accept interface.
diff --git a/parser/misc.go b/parser/misc.go
index c49a4f3aad..c448552a8e 100644
--- a/parser/misc.go
+++ b/parser/misc.go
@@ -248,6 +248,7 @@ var tokenMap = map[string]int{
 	"ENUM":                       enum,
 	"ESCAPE":                     escape,
 	"ESCAPED":                    escaped,
+	"EXCLUSIVE":                  exclusive,
 	"EVENTS":                     events,
 	"EXECUTE":                    execute,
 	"EXISTS":                     exists,
@@ -413,6 +414,7 @@ var tokenMap = map[string]int{
 	"SESSION":                    session,
 	"SET":                        set,
 	"SHARE":                      share,
+	"SHARED":                     shared,
 	"SHOW":                       show,
 	"SLEEP":                      sleep,
 	"SIGN":                       sign,
diff --git a/parser/parser.y b/parser/parser.y
index b0d107565f..5538397e6b 100644
--- a/parser/parser.y
+++ b/parser/parser.y
@@ -442,6 +442,7 @@ import (
 	engine		"ENGINE"
 	engines		"ENGINES"
 	escape 		"ESCAPE"
+	exclusive       "EXCLUSIVE"
 	execute		"EXECUTE"
 	fields		"FIELDS"
 	first		"FIRST"
@@ -483,6 +484,7 @@ import (
 	serializable	"SERIALIZABLE"
 	session		"SESSION"
 	share		"SHARE"
+	shared       	"SHARED"
 	signed		"SIGNED"
 	snapshot	"SNAPSHOT"
 	space 		"SPACE"
@@ -657,6 +659,7 @@ import (
 	LoadDataStmt		"Load data statement"
 	LocalOpt		"Local opt"
 	LockTablesStmt		"Lock tables statement"
+	LockClause         	"Alter table lock clause"
 	LowPriorityOptional	"LOW_PRIORITY or empty"
 	NumLiteral		"Num/Int/Float/Decimal Literal"
 	NoWriteToBinLogAliasOpt "NO_WRITE_TO_BINLOG alias LOCAL or empty"
@@ -1030,13 +1033,31 @@ AlterTableSpec:
 			NewTable:      $3.(*ast.TableName),
 		}
 	}
-|	"LOCK" eq "NONE"
+|	LockClause
 	{
 		$$ = &ast.AlterTableSpec{
 			Tp:    		ast.AlterTableLock,
+			LockType:   $1.(ast.LockType),
 		}
 	}
 
+LockClause: 
+	"LOCK" eq "NONE"
+	{
+		$$ = ast.LockTypeNone
+	}
+|	"LOCK" eq "DEFAULT"
+	{
+		$$ = ast.LockTypeDefault
+	}
+|       "LOCK" eq "SHARED"
+	{
+		$$ = ast.LockTypeShared
+	}
+|   	"LOCK" eq "EXCLUSIVE"
+	{
+		$$ = ast.LockTypeExclusive
+	}
 
 KeyOrIndex: "KEY" | "INDEX"
 
@@ -2326,7 +2347,7 @@ UnReservedKeyword:
 | "MIN_ROWS" | "NATIONAL" | "ROW" | "ROW_FORMAT" | "QUARTER" | "GRANTS" | "TRIGGERS" | "DELAY_KEY_WRITE" | "ISOLATION" | "JSON"
 | "REPEATABLE" | "COMMITTED" | "UNCOMMITTED" | "ONLY" | "SERIALIZABLE" | "LEVEL" | "VARIABLES" | "SQL_CACHE" | "INDEXES" | "PROCESSLIST"
 | "SQL_NO_CACHE" | "DISABLE"  | "ENABLE" | "REVERSE" | "SPACE" | "PRIVILEGES" | "NO" | "BINLOG" | "FUNCTION" | "VIEW" | "MODIFY" | "EVENTS" | "PARTITIONS"
-| "TIMESTAMPDIFF" | "NONE" | "SUPER"
+| "TIMESTAMPDIFF" | "NONE" | "SUPER" | "SHARED" | "EXCLUSIVE"
 
 ReservedKeyword:
 "ADD" | "ALL" | "ALTER" | "ANALYZE" | "AND" | "AS" | "ASC" | "BETWEEN" | "BIGINT"
@@ -3688,6 +3709,7 @@ GetFormatSelector:
 		$$ = strings.ToUpper($1)
 	}
 
+
 FunctionNameDateArith:
 	"DATE_ADD"
 |	"DATE_SUB"
diff --git a/parser/parser_test.go b/parser/parser_test.go
index 70bd04db8f..c1884d00b4 100644
--- a/parser/parser_test.go
+++ b/parser/parser_test.go
@@ -91,7 +91,7 @@ func (s *testParserSuite) TestSimple(c *C) {
 		"compact", "redundant", "sql_no_cache sql_no_cache", "sql_cache sql_cache", "action", "round",
 		"enable", "disable", "reverse", "space", "privileges", "get_lock", "release_lock", "sleep", "no", "greatest", "least",
 		"binlog", "hex", "unhex", "function", "indexes", "from_unixtime", "processlist", "events", "less", "than", "timediff",
-		"ln", "log", "log2", "log10", "timestampdiff", "pi", "quote", "none", "super",
+		"ln", "log", "log2", "log10", "timestampdiff", "pi", "quote", "none", "super", "default", "shared", "exclusive",
 	}
 	for _, kw := range unreservedKws {
 		src := fmt.Sprintf("SELECT %s FROM tbl;", kw)
@@ -1259,6 +1259,13 @@ func (s *testParserSuite) TestDDL(c *C) {
 		{"ALTER TABLE t ALTER COLUMN a DROP DEFAULT", true},
 		{"ALTER TABLE t ALTER a DROP DEFAULT", true},
 		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, lock=none", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, lock=default", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, lock=shared", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, lock=exclusive", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, LOCK=NONE", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, LOCK=DEFAULT", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, LOCK=SHARED", true},
+		{"ALTER TABLE t ADD COLUMN a SMALLINT UNSIGNED, LOCK=EXCLUSIVE", true},
 
 		// for rename table statement
 		{"RENAME TABLE t TO t1", true},