Abstract: Objective To compare the biological characteristics of spontaneous type 2 diabetic C57BL/KsJ-db/db mice in growth curve, glucose metabolism, serum insulin, weight of major organs，and organ coefficient with C57BL/Ks J-db/+ mice as the control, then the morphologic changes of the liver, kidney and pancreas were observed. Methods Forth weeks old mice were used with total of twenty weeks experimental period, the weight and glucose at each week, serum insulin at every two weeks were measured. After the experimental period, the mice were sacrified, and the organ and fat were weighted. The pathological changes of the liver, kidney and pancreas were observed. Results ① The weight, glucose and serum insulin of db/db mice were higher than those of the control group at the same age(PP<0.01). But the spleen，pancreas and kidney was less relatively, especially of the spleen and pancreas in female mice(P<0.01).③ The liver appeared significant cell putrescence, adipose degeneration, inflammatory cell infiltration and fibroplastic proliferation in db/db mice. The renal interstitial appeared hyperaemia, dropsy, hyaline cast in renal tubules, and adipose degeneration of epithelial cell. At the same time，the number of glomeruli pancreatici and islet cells decreased obviously. Conclusions The db/db mice is a suitable disease model of type 2 diabetes mellitus, which shows hyperglycemia, high insulin resistance，insufficiency of islet function, renal and hepatic alterations.

Key words: Type 2 Diabetic, db/db mice, Blood Glucose, Serum Insulin, Tissue Injury