AIM: To observe the effects of Corydalis decumbens Pers Injection(CDPI) on the learning,memory and Ang-1 expression of hippocampus in vascular dementia rats,and to explore the protective mechanisms. METHOD: The VD model rat model was established by the ligation of both carotids of the rat.Morris water-maze was used to examine the ability of spatial learning and memory of VD model rats.Hippocampal histopathological change was observed through optical microscope after being stained with Hematoxylin-eosin(HE).The semi quantitative analysis of Ang-1 expression in hippocampus was analysed by BI2000 image analysis system after immunohistochemistry staining. RESULTS: In the place naviga test,the mean escape latency significantly shorted and the explporing distance obviously decreased in CDPI 2 mg/kg、5 mg/kg groups after one month and two months compared with model group.After two months with CDPI treatment,Ang-1 exprssion of hippocampus increased in VD rats. CONCLUSIONS: CDPI can improve the ability of spatial learning and memory.The mechanism may be related to increasing expression of Ang-1 in hippocampus.