Objective To observe PDX-1 expression in the pancreas of type 2 diabetic rat model and effects of rosiglitazone (RGZ) on it. Methods Type 2 diabetic rat model was induced by long-term feeding with high-fat foods followed by a single intraperitoneal injection of low dose of streptozotocin (STZ). The morphological changes of pancreas were examined by microscopy and immunohistochemistry. The mRNA levels of PDX-1 and insulin were determined by RT-PCR. PDX-1 protein expression was detected with Western blot. Results The percentage of insulin-positive cells(12.75±2.18)，the average optical densities of PDX-1-positive area(0.240±0.051)，PDX-1 mRNA level (0.153±0.071)and PDX-1 protein level(0.253±0.028) were significantly lower in untreated diabetic rats than in the controls(42.61±2.68，0.648±0.087，0.49±0.032，0.720±0.036 respectively)(all P＜0.01)，and in RGZ-treated versus untreated group those parameters increased significantly (all P＜0.05~0.01). Conclusions Rosiglitazone could protect islet cell function，and improve PDX-1 expressions in both mRNA and protein levels.