OBJECTIVE: To study the improvement effect of geniposide on cognitive dysfunction in model rats with diabetes. METHODS: 50 rats were randomly divided into blank control group (distilled water), model group (distilled water) and geniposide low-dose, medium-dose, high-dose groups (5, 10, 20 g/kg), 10 in each group. Except for blank control group, rats in other 4 groups were fed with high-sugar and high-fat diet and injected streptozotocin to induce diabetes model. After modeling, rats in each group intragastrically administrated relevant medicines, once a day, for 8 weeks. After last administration, fasting blood glucose (FPG), glycosylated hemoglobin (HbA1c) levels, escape latency period in Morris water maze test, and correct rate of behaviors in Y maze test of rats in each group were detected. RESULTS: Compared with blank control group, FPG, HbA1c levels of rats in model group were obviously increased, escape latency period was obviously prolonged, correct rate of behaviors in Y maze test was obviously decreased, with statistical significances (P<0.05). Compared with model group, above-mentioned indexes in geniposide groups were obviously improved (P<0.05), which were positively correlated with dose (P<0.05). CONCLUSIONS: Geniposide can effectively reduce blood glucose level of model rats with diabetes and improve their cognitive dysfunction.