Abstract: In this paper,the amorphous silicon（a-si:H） was obtained on glass using plasma enhanced chemical vapor deposition（PECVD） method.The crystallization transition from a-si to nc -si was performed using frequency -doubled Nd:YAG laser with a flat -top beam.The crystalline and microstructure of the laser interference crystallized samples were investigated by X-ray diffraction,Raman spectra and Atomic Force Microscopy（AFM）.The best laser energy influence is 800mJ/cm and the mean crystal grain size is 30～50nm.