Zinc oxide films were prepared on n type Si(100) substrate using femtosecond laser deposition with laser parameters as follows: pulse width 50 fs, wavelength 800 nm, repeat frequency 1 kHz, and pulse energy 2 mJ. The effects of substrate temperature change and annealing on the structure, surface morphology and optical properties of the ZnO films were discussed. The X-ray diffraction (XRD) results showed the ZnO films deposited under different temperature (20～350 ℃) were with wurtzite structure and highly c-axis oriented. When the substrate silicon was 80 ℃ the film was highly (002)-oriented, and (103)-oriented at 500 ℃. The nano-crystal structure of the films and hexagonal structure of ZnO were observed with a field-emission electron microscope (FEEM). The effects of substrate temperature and annealing on the optical transmissivity of ZnO films were discussed by transmitted spectra, and the transmissivity was increased after annealing.