Objective To investigate the cytotoxic effects of IL-2 combined with different dosages of sorafenib on renal cellular carcinoma cell line 786-0. Methods Renal carcinoma cell 786-0 was cultured. Then , IL-2 (20 μmol/L) combined with different dosages of sorafenib (6.9, 13.8, 20.8 μmol/L) were used to treat tumor cell 786-0. The inhibitory effect on cell proliferation was determined by MTT assay. Cell apoptosis was measured by Annexin V-FITC kit. The tumor-bearing mice models were established and divided into four groups. Results The tumor cell growth was inhibited with the time-course correlation in all groups. In the 48-hour high doses group, the inhibitory rate was up to (74.67±1.87) %. The rates of cell proliferation inhibition and cell apoptosis were higher in the high dosages group than those in the other groups. Conclusions Immunotherapy combined with target therapy could significantly inhibit the growth of renal cellular carcinoma. But we should find a proper dosage, which could improve the clinical effect and reduce the adverse effect.