Objective To study the effects of pioglitazone on the expressions of peroxisome prolifer-ator-activated receptor-γ(PPAR-γ) in hippocampus and hypothalamus of diabetic rats and to explore the as-sociation between pioglitazone and cognitive function. Methods Thirty male SD rats were equally randomized into control group (C group)，diabetic group (D group) and diabetes+pioglitazone group (DP group). The spatial learning and memory function were tested by Morris water maze after 8 weeks. Expressions of PPAR-γin hippo-campus and hypothalamus were detected by Western Blot. Results In the Morris water maze，escape latencies of D group increased significantly compared to C group and DP group(P ＜0.05). The expressions of PPAR-γin hippocampuses and hypothalamuses of D group were significantly lower than C group and DP group(P ＜0.05).Conclusions Pioglitazone could increase the expressions of PPAR-γin hippocampus and hypothalamus of dia-betic rats，which may be related to the improvement of spatial learning and memory function caused by pioglita-zone.