Objective To investigate the role of basophils in the imbalance of Th1/Th2 response in mouse models of collagen-induced arthritis(CIA). Methods 4-6-weeks old C57/BL6 mice were immunized with collagen at multiple points on the back and foot twice (0 and 3 weeks) to establish a mouse model of collagen-induced arthritis. Blood samples were collected before the first immunization and 1, 3, 6 and 9 weeks after immunization, and cells from lymph nodes were collected. Flow cytometry and ELISA were employed to detect the levels of basophils and IL-4, and the joint swelling was scored. Results Mouse model of CIA was successful established. The ratio of IL-4/IFN-γ of the CIA group was significantly lower than that in the mice before CIA modeling and the control group, indicating a Th2-dominant response. At the same time, the peripheral basophils counting and percentage of IL-4 positive basophils of the CIA group were significantly higher than those of the control group. While, the IL-4/IFN-γ ratio of the CIA group was significantly higher than that of the control group, indicating a Th1-dominant response. The peripheral basophils counting of the CIA group was slightly lower than that of the control group.Conclusions Basophils may participate in the development of CIA in mouse models through affecting the imbalance of Th1/Th2 response.