An embodiment of a laser crystallization method includes providing a substrate on which an amorphous silicon thin film is deposited, positioning a laser mask over the substrate, the laser mask including a mask pattern that contains transmitting regions and a blocking region, irradiating a first laser beam onto a surface of the substrate through the pattern of the laser mask to first crystallize a predetermined region of the silicon thin film, moving the laser mask or a stage on which the substrate is loaded in an X-axis direction to perform second crystallization using the laser mask, repeatedly performing the crystallization to an end of the substrate in the X-axis direction, moving the laser mask or the stage in a Y-axis direction, and repeatedly performing the crystallization in the Y-axis direction to complete crystallization.