The knee joint is one of the most commonly affected large joint in rheumatoid arthritis (RA). Its progression often causes joint destruction and deformity. The cartilage injury, bone marrow lesions and synovitis scores of the knees at baseline, P-1 (1 year prior to P0), and P0 (time of onset of RA) were evaluated using the MOAKS score. The generalized estimation equation (GEE) was used to compare the MR scores of knee joints at three time points to observe the longitudinal changes. The changes of bone marrow lesions and synovitis scores in knee joints were significant before the occurrence of RA.