Abstract: The atomic oxygen（AO）is one of the most important factors in low earth orbit（LEO）environment.Chemical property of AO is very active,and can oxide most of polymeric materials.Spacecraft polymeric materials can be significantly eroded as a result of exposure to atomic oxygen in LEO.The paper provides an overview of the recent developments in AO environment and AO protection methods.The advantage,disadvantage and research progress of organic,inorganic and hybrid coatings are discussed.Further development trends are proposed.