Objective: To investigate the effects of recombinant human growth hormone (rhGH) and 5-fluorouracil(5-Fu) on human colon carcinoma LOVO cells in vitro. Methods: The LOVO cells during exponential growth stage were harvested and divided into control group,GH group, 5-Fu group and GH + 5-Fu group. According to the dose of GH, the GH group was separated into two sub-groups(50 ng/mL and 100 ng/mL) and the GH +5-Fu group was separated into two sub-groups. With different concentrations of rhGH and/or 5-Fu , the cell survive rates were analyzed by MTT assay after 24 h , 48 h and 72 h and cell cycle and proliferation index (PI) were analyzed by flow cytometry after 24 h. Results: Compared with the control group, the survive rates in 5-Fu and GH +5-Fu groups were decreased significantly (P <0. 05). The significant effects of rhGH on cell cycle kinetics were found in the cell line. Compared with the control group, percentage of S phase and proliferation index (PI) significantly increased (P <0.05)and percentage of G_0/G_1 phase decreased (P <0. 05) in GH groups. Percentages of cells of S phase and PI significantly decreased in GH + 5-Fu groups (P < 0. 05). Rate of apoptosis increased in 5-Fu and GH +5-Fu groups (P <0.05). Compared with the 5-Fu group, there were no statistically significant differences in percentages of cells of S phase and PI and rate of apoptosis between two GH+5-Fu groups(P >0. 05). Conclusion-. rhGH does not stimulate the LOVO cells proliferation in vitro, and its use is safe when combined with 5-fluorouracil.