BACKGROUND: Human umbilical cord blood stem cells have been widely used in the study of spinal cord injury, but in vitro differentiation of human umbilical cord blood stem cells (hUCBSCs) has been limited by various factors. Mongalian medicine axillary choerospondias fruit extract has protective effects on neural cells, but the action mechanisms are unclear. OBJECTIVE: To observe promoting effects of 3 kinds of Mongalian medicine axillary choerospondias fruit extracts on in vitro differentiation of hUCBSCs. METHODS: Fresh umbilical cord blood was obtained from healthy puerperants to prepare hUCBSC suspension. The purified hUCBSCs were incubated in 40 petri dishes. The Mongalian medicine axillary choerospondias fruit extracts were divided into: sample 1 group: ethanol extraction, ethyl acetate extraction, crude drug mass concentration was 8.25 g/mL; sample 2 group: ethanol extraction, NKA resin isolation, 10% ethanol eluting concentration, crude drug mass concentration was 1.72 g/mL; sample 3 group: ethanol extraction, NKA resin isolation, 70% ethanol eluting concentration, crude drug mass concentration was 2.41 g/mL; control group: incubation of 80% DMEM containing 20% calf serum. Effects of various mass concentrations of Mongalian medicine axillary choerospondias fruit extract on hUCBSCs proliferation were observed. Proportion in S phase was measured using flow cytometry at 24 and 72 hours. RESULTS AND CONCLUSION: The proliferation of hUCBSCs was not significant in the sample 3 group. At day 10, the proliferation was significantly greater in the sample 1 and 2 groups compared with the sample 3 and control groups (P < 0.01). The number of hUCBSCs was significantly increased at 24 and 72 hours in S phase in the sample 1 and 2 groups. Mongalian medicine axillary choerospondias fruit extract (crude drug mass concentration 8.25, 1.72 g/mL) could promote in vitro proliferation of hUCBSCs.