The preparation method, phase change transformation properties, optical spectra properties and shortwavelength optical storage properties of Ge0.45Te0.55 phase change thin film are reported. The film is prepared by RF-magnetron sputtering technology. The deposited films are amorphous. The crystallization temperature is about 190 ℃, the reflectivity of the crystalline state film is about 50%. A static optical recording tester with an focused Argon laser beam (514.5 nm) irradiating on the films is used to evaluate the optical storage performance. The results show that a reflectivity contrast larger than 15% can be obtained with the low power and short pulse width laser beam. These results indicate that the Ge0.45T0.55 thin film is a promising candidate for high reflectivity and high density compact diskerasable system as the recording material.