Abstract: Objective To report 2 cases of lipoma arborescens in order to avoid its misdiagnosis and mistreatment. Methods Two cases of lipoma arborescens were reported and literature on its clinical symptoms,diagnosis and treatment was reviewed. Results No specific clinical manifestations of lipoma arborescens were found.Its final diagnosis was mainly dependent on the pathology of synoovium and synovectomy was the main treatment procedure for it. Conclusion Lipoma arborescens is an extremely rare disease with unknown etiology.It is usually manifested as swelling and recurrent joint effusion.Laboratory test shows no specific findings.It usually occurs in the knee joint and is easily misdiagnosed as osteoarthritis and spondyloarthritis,etc.