Objective To explore the influence of Tongmaiyizhi capsule on ability of learning and memory and morphology of hippocampus in vascular dementia model rats.Methods Animal models with vascular dementia were prepared by cerebral ischemia-reperfusion at hyperlipidemia model rats.We observed the rats' ability of learning and memory in the y-type electric maze and the change of morphology of hippocampal CA1 sector by the TEM and light microscopy.Results The electric maze experiment showed that ability of learning and memory obviously decreased in model rats,nevertheless the change of ability of learning and memory in group with Tongmaiyizhi had significant effect compared with model rats.Morphological observation indicated that the nerve cell decreased in number,arranged in disorder,and partly nuclei deeply stained,degenerated,in CA1 sector of hippocampus of the model rats.TEM showed that for nerve cell,the membrane folds invaginated,the nuclei degenerated,the chromatin condensed and margined,and the organelles arranged in disorder.Under the TEM and light microscopy,nerve cell morphology of Tongmaiyizhi group had clear amendment compared with the model group.Conclusion Tongmaiyizhi capsule can protect the nerve cell in CA1 sector of hippocampus of the VAD rats,so it improves the ability of learning and memory.