Objective To observe the effects of Huoxue huatan Formula cognitive fuction and acetylated p53 in congnitive impairment rats. Methods By bilateral common carotid artery occlusion to establish chronic cerebral ischemia model of rats， the learning and memory ability of the rats in each gruop were evaluated after the intervention of Huoxue Huatan Formula in 4 weeks by using Morris water maze test and Spatial probe test and detecting the contents of acetylated p53 changes by wesern blot. Results After 4 weeks of treatment， that escape latency period were found inceased while the times crossing the platform decreased which could inhibited by the decoction. The acetylated p53 expression were found decreased in frontal cortex， hippocampus and the nucleus accumbens of the rats. Conclusions HuoXue Huatan Formula could significantly improve cognitive function in congnitive impairment rats. The mechanism could be attributed to its inhibiton of Acetylated p53.