【Abstract】Objective To investigate the effects of human growth hormone (GH) on colonic cancer cells to provide experimental evidence about the GH safety in colonic cancer therapy. Methods The nude mouse model of colonic carcinoma induced with SW480 cell line was established to observe the effects of GH on the transplanted carcinoma. GH and 5-FU were administered to SW480 cells cultured in vitro to observe the cell growth with MTT method. Results The volume, average diameter and weight of the transplanted carcinoma in GH group were significantly higher than those in control group（P＜0.05）. In vitro, the value of A in GH group was significantly higher than control group （P＜0.01), but the value of A in 5-FU+GH group was lower than control group（P＜0.01）. Conclusion GH can promote colonic cancer cell growth; GH combined with cell cycle specific chemotherapeutic drugs is safe in colonic cancer therapy and may be used as a promoter of chemotherapy.