[Objective] To research the effect of oleanolic acid(OA) on vascular endothelial growth factor(VEGF) and microvessel density(MVD),and investigate its anti-cancer mechanism.[Methods] 32 mice were randomly divided into 4 groups,i.e.oleanolic acid high dose group(100 mg/kg·d),oleanolic acid low dose group(50 mg/kg·d),fluorouracil group(5-Fu)(positive control,50 mg/kg·d),and normal saline group(negative control).The mice in former three model groups were administered by intraperitoneal injection,and those in normal saline group were intragastric administrated on the 8th day for 14 days.After stopping administration,the tumor blocks were taken out of the mice on the next day and carried out routine organization morphological observation,in the mean time,liver function indexes AST and ALT were detected,VEGF and MVD in tumor were determined by immunohistochemical method.[Result] The tumor weights in OA groups were obvious lower than that in normal saline control group,and the difference between which was significant(P<0.01);the intensive degree of vascular in OA group and 5-Fu were obvious lower compared with that in normal saline group.Oleanolic acid could inhibit the activities of AST and ALT effectively,and the contents of AST in OA groups were much higher than that in normal saline group with significant difference(P<0.01).The expression levels of VEGF and MVD in model groups were significantly higher than that in blank control group(P<0.01),and which were the highest in normal saline group.[Conclusion] Oleanolic acid can inhibit the growth of cancer cell in vivo significantly and repair the liver damage caused by transplanted hepatocarcinoma,and its anti-cancer mechanism may be related to the expression of VEGF and MVD. [Objective] To research the effect of oleanolic acid (OA) on vascular endothelial growth factor (VEGF) and microvessel density (MVD), and investigate its anti-cancer mechanism. [Methods] 32 mice were randomly divided into 4 groups, ieoleanolic acid high dose group (100 mg / kg · d), oleanolic acid low dose group (50 mg / kg · d), fluorouracil group (5-Fu) The mice in former three model groups were administered by intraperitoneal injection, and those in normal saline group were intragastric administered on the 8th day for 14 days. After stopping administration, the tumor blocks were taken out of the mice on the next day and carried out routine organization morphological observation, in the mean time, liver function indexes AST and ALT were detected, VEGF and MVD in tumor were determined by immunohistochemical method. [Result] The tumor weights in OA groups were obvious lower than that in normal saline control group, and the difference be The intensive degree of vascular in OA group and 5-Fu were significantly lower than with normal saline group. Oleanolic acid could inhibit the activities of AST and ALT effectively, and the contents of AST in OA groups were much higher than that in normal saline group with significant difference (P <0.01). The expression levels of VEGF and MVD in model groups were significantly higher than that in blank control group (P <0.01), and which were the highest in normal saline group. [Conclusion] Oleanolic acid can inhibit the growth of cancer cell in vivo significantly and repair the liver damage caused by transplanted hepatocarcinoma, and its anti-cancer mechanism may be related to the expression of VEGF and MVD.