Abstract: This paper discusses the space atomic oxygen environment as well as its erosion and damage effects on spacecraft surfaces. The studies on the atomic oxygen protection technology carried out in BISEE (Beijing Institute of Spacecraft Environment Engineering) are introduced. During the past five years, atomic oxygen protective coatings were developed based on the physical vapor deposition (PVD) and sol-gel method in BISEE, and their anti-AO performance was evaluated by testing. Preliminary results indicate that these protective coatings enjoy good resistance to atomic oxygen erosion.