Objective To observe the changes of inflammatory cytokines in collagen-induced arthritis (CIA) rats. Methods The CIA model was established. The body weight, volume and thickness of hind paws, arthritic index were measured; the pathological change of arthral synovial tissues was observed by HE staining with light microscope; the levels of TNF-α, IL-1β and IL-6 in the serum were detected by enzyme-linked immunosorbent assay (ELISA) on the day 10, 20, 30, 40, 50 and 60 after the first immunization. Results The inflammatory reaction was approximately appeared on the 14th day, the most seriously state on the 30th day, and then gradually decreased following the time. The concentrations of TNF-α increased on the 10th day (P<0.01), and the concentrations of IL-1β and IL-6 increased on the 20th day after the first immunization (P<0.05). The peak concentrations of TNF-α, IL-1β and IL-6 were all on the 30th day (P<0.01), and then gradually decreased following the time. Conclusion TNF-α, IL-1β an IL-6 play important roles during the whole course.