Objective: Three-dimensional structure and histological research was performed on Bone marrow edema (BME) region of Rheumatoid arthritis (RA),and to explore the effect of bone edema on the strength of bone structure. Methods：Patients with RA who were scheduled for total knee arthroplasty(TKA),were recruited for this study.MRI images were used to identify BME in the subchondral bone of the tibial plateau. Micro-CT was used to scan and reconstruct the specimen. The region of interest was selected to detect bone mass and trabecular bone related indicators,and histological features were observed by tissue section. Results: From January 2016 to May 2018,16 knees of 16 patients were enrolled.Compared with the control region,the bone quantity related parameters,including bone mineral density(BMD)and bone volume fraction(BV/TV), were significantly decreased.The trabecula structure related parameters in BME region were also significant different from those of the control region except trabecula thickness(Th.Th),among which trabecular separation(Th.S), trabecular bone pattern factor(Tb.Pf) and structure model index (SMI) raised，while trabecular number(Tb.N) decreased.Tissue specimens revealed trabecular bone destruction accompanied with lymphocytes infiltration and angiogenesis in BME region. Conclusion: There are active inflammatory reactions in the BME region of RA. Bone quantity decrease and trabecula bone structure destruction may lead to decrease of local bone strength and joint destruction in the following stage.