Abstract: PVDF/TiO₂ composite film was prepared via casting，the thermostahility, mechanical property, crystalline form, thermal performance and weather resistance of the composites films were studied. It showed that when the mass ratio of PVDF/TiO₂=98/2，the tensile strength of the composites films reached 59. 5 MPa.  However，the initial decomposition temperature was lowered to 340 ℃，which was compared to neat PVDF film.  The degree of crystallinity of PVDF was not changed so much by the incoporation of TiO₂.The weather resistance of PVDF/TiO₂ composites films was improved obviously according to ultraviolet radiation tests.

Key words: polyvinylidene fluoride;titanium dioxide, composite film, weather resistance;mechanical property, thermostahility property