Abstract: Objective: To explore whether pentoxifyline（PTX） has the protection on the treatment of collagen-induced arthritis in rats by inhibiting tumor necrosis factor-α. Methods: Wistar rat arthritis was induced by bovine II collagen（BIIC）.The rats were randomly divided into three groups including normal control group,CIA group treated with normal saline and PTX group.The body weight,the hind paw volumes,the arthritic index of all rats at different time points were observed and measured.The serum TNF-α level of every group at different time point was detected by ELISA. Results: There was no difference between PTX group and normal control group（P＞0.05） at the 48th day,and the TNF-α level of PTX group was less than that of CIA group（P＜0.05） at the 48th day. Conclusion: Pentoxifyline significantly ameliorates the symptoms of CIA rats,and inhibits the development of inflammatory swelling.PTX can significantly decrease the serum TNF-α level.PTX may play role of anti-inflammation by inhibiting the serum TNF-α level.