Objective To explore the effect of Yizhi Jiedu Decoction on the learning and memory ability,glucose and lipid metabolism and insulin secretion in diabetic rats.Methods Forty-eight SD rats were randomly divided into normal control group,diabetes model group,low-dose,medium-dose,high-dose Yizhi Jiedu Decoction groups,and donepezil hydrochloride groups,each with eight rats.Except for the normal control group,the other five groups were given a high-sugar and high-fat diet combined with streptothricin to induce diabetes.low-dose,medium-dose,high-dose Yizhi Jiedu Decoction groups were given orally by 0.9,1.8,3.6 g/（ kg·d） respectively,donepezil hydrochloride group was given donepezil hydrochloride by 0.45 mg/（ kg · d）.After four weeks of continuous gastric gavage,the rat body weight,fasting insulin（ FINS）,fasting blood glucose（ FBG）,serum total cholesterol（ TC）,low-density lipoprotein cholesterol（ LDL-C）,high-density lipoprotein cholesterol（ HDL-C）,and triglycerides（ TG） were measured, and the behavioral changes of rats and the pathological changes of hippocampal neurons were observed.Results Compared with the diabetes model group,the weight of the rats in the high-dose Chinese medicine group was controlled（ P < 0.05）,FBG,TG,and LDL-C were significantly reduced（ P < 0.01,P < 0.05）; the rats’ escape latency was significant shortened（ P < 0.05）,and the number of crossing platforms increased（ P < 0.05）; pathology suggested that the nucleus pyknosis was decreased,the number of degenerated necrotic cells decreased,and the number of Nissl bodies increased.Conclusion Yizhi Jiedu Decoction can significantly improve the glucose and lipid metabolism disorder,promote the secretion of insulin,and improve the cognitive dysfunction of diabetic rats.