1kHz femtosecond laser was used to induce crystallization on amorphous Si film. Raman spectra show that the crystallization region depended critically on the laser fluence and profile. Furthermore, a textured surface with a mass of finegrained crystalline Si was observed through SEM. This structure might result from the explosive crystallization and epitaxial growth of Si nucleation on the interface of liquidsolid Si. Due to the simultaneous process of crystallization and surface texturing, this laser treated region enhanced its absorbance in the visible and infrared band.