Objective: To study the inhibiting effect of rh-endostatin combined with ginsenoside Rg3 on growth of breast cancer xenografts. Methods: C57BL/6 nude mice were selected as research subjects, animal models with breast cancer xenografts were established through subcutaneous injection of breast cancer cells in the neck and randomly divided into A-D groups, and normal saline, rh-endostatin, ginsenoside Rg3 and rh-endostatin combined with ginsenoside Rg3 were injected respectively. Tumor growth, serum angiogenesis factor contents, percentages of cell cycles and expression levels of cell cycle-related molecules in tumor tissue of four groups were compared. Results: 7 d, 14 d and 21 d after treatment, tumor volume as well as serum VEGF and bFGF contents of B group, C group and D group were significantly lower than those of A group, and tumor volume as well as serum VEGF and bFGF contents of D group were significantly lower than those of B group and C group; 21 d after treatment, tumor weight, percentages of S phase and G2/M phase as well as mRNA contents and protein contents of cyclin E and CDC25A in tumor tissue of B group, C group and D group were lower than those of A group, and G0/G1 phase percentages were higher than that of A group; tumor weight, percentages of S phase and G2/M phase as well as mRNA contents and protein contents of cyclin E and CDC25A in tumor tissue of D group were significantly lower than those of B group and C group, and G0/G1 phase percentage was lower than those of B group and C group. Conclusion: rh-endostatin combined with ginsenoside Rg3 can more effectively inhibit growth of breast cancer xenografts, make cell cycle arrest and down-regulate expression of cell cyclerelated molecules.