The third subunit of the COP9 signalosome (COPS3) is associated with cell proliferation and tumorigenesis process in cancer. The present study showed that the expression level of COPS3 was upregulated in malignant cell lines and COPS3 overexpression was related with clinical stage, T stage, historical grade. Kaplan–Meier survival curves showed that COPS3 may function as a prognostic factor for overall survival. CCK–8 and colony formation assays revealed that knockdown of COPS3 in ACHN and 786–O significantly impacted proliferation in vitro. In addition, flow cytometry showed that inhibition of COPS3 induced G0/G1 arrest and promoted apoptosis. COPS3 may promote kidney cancer progression by altering Phospho–AKT(Thr308), Cyclin D1 and Caspase–3 expression. Collectively, Our findings suggest that COPS3 may be a new potential target of ccRCC.