Objective To study the therapeutic effect and Immunomodulatory mechanism of Qubi Formula（ImpedimentDispelling Formula）for typeⅡcollagen-induced arthritis（CIA）in rats.Methods Totally 72SD rats were randomized into the blank control group

model group

tripterygium glycosides group

Qubi Formula high-dose group and Qubi Formula lowdose group

with 12

15

15

15and 15in each.The CIA models were induced by subcutaneous injection of collagen typeⅡ and incomplete Freund’s adjuvant on the tail root of rats in all groups except the blank control group.On the 15th day of modeling

the Qubi Formula high-dose and low-dose groups were gavaged with 6.66g/（kg·d）and 3.33g/（kg·d）Qubi Formula suspension

the tripterygium glycosides group was gavaged with 9.68mg/（kg·d）tripterygium glycosides suspension and the blank control group and model group were gavaged with equal volume of pure water once daily for 4 weeks.The pathological damage of joints in each group was observed and semi-quantitative score was calculated.The contents of anti-type II collagen antibodies（COL-2）

interleukin-1β（IL-1β）and interleukin-6（IL-6）were detected.Results Comparing with the blank control group

the score of knee joint pathology and contents of COL-2

IL-1βand IL-6were significantly increased in the model group（P<0.05or P<0.01）.Comparing with the model group

the score of knee joint pathology and contents of COL2

IL-1βand IL-6were significantly decreased in the Qubi Formula high-dose group and tripterygium glycosides group（P< 0.05or P<0.01）.Comparing with the Qubi Formula low-dose group and tripterygium glycosides group

the score of knee joint pathology and contents of COL-2and IL-1βwere significantly decreased in the Qubi Formula high-dose group（P<0.05or P<0.01）.Conclusion High-dose Qubi Formula can obviously alleviate knee injury in CIA rats that may be relevant to reducing the COL-2level and down-regulating the contents of IL-1βand IL-6.