Abstract: The organic/inorganic hybrid silica coatings were prepared on Kapton substrate by sol-gel process,using tetraethoxysilane(TEOS) and 3-(methacryloxypropyl)-trimethoxy silane(MEMO) as precursors.The experiment results of atomic oxygen with ground simulation device show that the erosion yield of the silica-coated Kapton is one order less than that of the pristine Kapton.Comparatively,the silica coating with 0.2 MEMO presents better AO-ersion resistance.After AO exposure,the coated Kapton can keep optically stable.The analysis results of SEM,FTIR-ATR and XPS indicate that after AO exposure,the characteristic peak of Si-O-Si bonds shifts to that of Si-O bonds of SiO2,and the intensity of Si 2p state peak from MEMO decreases.Therefore,the coating structure tends to transfer to stabile SiO2.