Objective To explore the influence of Mac-1 deficiency on tumor growth of melanoma. Methods The population of Mac-1 gene knock-out (Mac-1^-/-) mice was expanded. B16-F10 cells were subcutaneously injected into the C57BL/6J mice (control group) and Mac-1^-/-mice (experiment group), respectively. Subsequently,the survival rate, tumor volume and body weight were recorded. The proliferation and infiltration of macrophages were detected by immunohistochemistry. Results The survival rate of Mac-1^-/- mice was significantly improved compared with the C57BL/6J mice (P<0.001). The tumor volume and body weight were remarkably decreased in the Mac-1^-/- mice compared with the control group (P<0.001). Meanwhile, the tumor cell proliferation index was decreased in the Mac-1^-/- mice compared with the control group (P<0.01).Furthermore, the infiltration of macrophages in the tumor tissues was also decreased in Mac-1^-/- tumor mice compared with control group. Conclusions Mac-1 gene deletion can significantly suppress melanoma growth.