To observe effect of Tongbi Application Powder on Freunds adjuvant knee arthritis in rats and its mechanism. Methods:Rats were randomly divided into model group and treatment group， sc. injected Freunds adjuvant 0.1ml into right knee， then measured interleukin -1 beta (IL-1 β)， hyaluronic acid (HA) before surgery，1wk， 2wk， 3wk after surgery; measured volume below the right toe. Results:After wk2， treatment group had lower IL-1 beta and higher HA levels， significantly different compared with that before treatment and model group (P<0.05). The treatment groups extent of foot swelling and duration was significantly better than that of model group， (P<0.05). Conclusion:Tongbi Application Powder is effective for treating Freunds adjuvant arthritis in rats， the effect may be induced by inhibiting IL-1 β synthesis and increasing HA level.