Abstract: In order to prove the importance of exogenous interleukin-17（IL-17） antibody in defending against Staphylococcus aureus skin infections, in this experiment the back of mice was inoculated with the mixture of Staphylococcus aureus 923 with IL-17 antibody（antibody group） or immunoglobulin G2 A（same type control group）. The wound sizes of the infected site of the mouse after inoculation, the number of bacteria in the blood 11 days after inoculation, the number of bacteria in each organ, mouse body weights, the weights of the kidney, lymph node and spleen, and the organ indexes were studied. The results showed that after the mice was inoculated with the mixture, the wound size of the infected site in the antibody group was significantly larger than that of the same type control group on the 3 rd and 5 th day（P＜0.05）. The number of bacteria per unit volume of blood in the antibody group was extremely significantly higher than that of the same type control group（P＜0.01）;the number of bacteria in the heart and lungs per unit weight was significantly higher than that in the same type control group（P＜0.05）. The body weight gain of mice in the antibody group was higher than that in the same type control group on day 3 after inoculation with the mixture; from day 5 to day 11,the body weight gain of mice in the same type control group was higher than that of the antibody group, but the body weight gain between the two groups did not reach statistical difference（P＞0.05）. The weights of the kidney, spleen and lymph node and organ indexes were not statistically significant between the two groups（P＞0.05）. The results suggested that IL-17 antibody could directly react with IL-17 produced by the body after being mixed with Staphylococcus aureus and being injected into the back skin of mice, preventing IL-17 from playing the role of resisting Staphylococcus aureus skin infection, and further confirmed the importance of IL-17 in resisting Staphylococcus aureus skin infection.