Objective:To explore the effect of recombinant growth hormone on cholangiocarcinoma in vivo,and study the possible mechanism of IGFBP3. Methods:Athymic nude mice were injected with QBC939 cells. When tumor became palpable obviously,animals were randomized to receive GH(GH groups:4 mg 2w,4 mg/kg.s.c. once daily for 2 weeks;2 mg 2w,2 mg/kg.s.c. for 2 weeks;2 mg 3w,2 mg/kg.s.c. for 3 weeks) versus saline control(NS groups). Animals and tumour were weighed,tumor and carcass weight rate were determined. Cells of tumor tissues were evaluated by flow cytometry(FCM). Western blot was used to detect IGFBP3 in mice liver. Results:There was no statistical significance of the difference on the host features(body weight,tumor weight,tumor and carcass weight rate,P > 0.05) or the cell cycle kinetics(G1,G2M,S,PI,P > 0.05) between GH groups and NS groups in vivo. Compare with NS groups,the expression of IGFBP3 in GH groups in mice liver was significantly increased according to the dose of GH[(2 mg/(kg·d):(0.63 ± 0.05) vs (0.28 ± 0.05),and 4 mg/(kg·d):(0.71 ± 0.07) vs(0.28 ± 0.05),respectively,P > 0.01]. Conclusion:GH couldn’t accelerate tumor growth in vivo,and the possible mechanism was acted by the effect of IGFBP3.