The utility model relates to a stair especially relate to stair and mark time. A cross -section is orthogonal section bar, and its length is matchd with the stair tread run that stair protector that marks time, it is one and is become by the glass steel to the knot is on the angle that stair were marked time, and is porose on this protector's the both sides face, the downthehole screw fixation that is equipped with the nylon expansion pipe and marks time with wrong income. The utility model discloses can make stair mark time obtains intact protection.