To observe the mechanism of Xingzhi granule for improving learning ability and memory of rats with vascular dementia. Methods: A total of 120 SD rats were randomly divided into sham operation group, model group, control group and high-dose group, middle dose group and small dose group; 20 rats in each group. The mice were given orally with corresponding drugs 2 times a day for 14 days. By the 8-14 days, the rats were tested for spatial learning and memory, and their Ach in hippocampus and somatostatin(SS) levels were measured. At the same time, we conducted plasma test to measure thromboxane B2 (TXB2), 6-keto prostaglandin (6-Keto-PGF1 alpha) level. Results: Compared with the sham operation group, model group rats hippocampal ACh and SS decreased significantly, significantly increased plasma TXB2 and 6-Keto-PGF1αsignificantly reduced. Compared with the model group, control group and other groups given different does of Chinese Medicine not showed significant influence on the activity of Ach. Chinese Medicine high dose group、middle dose group could significantly increase the content of SS in hippocampus. In each group, TXB2 was decreased and 6-Keto-PGF1 was increased. By 14th day, compared with the sham operation group, escape latency of model group was prolonged; compared with the model group, control group, Chinese Medicine high dose group, middle dose group could significantly shorten the escape latency. Conclusion: Xingzhi granule has good effect on improving learning ability and memory of rats with vascular dementia. The mechanism may be related to the increase of SS content in the hippocampus and returning balance of TXB2 and 6-Keto-PGF1ɑ so that improve brain function.