Abstract： Objective Aim To explore the relationship between gastric emptying and expression of leptin and its receptor in different diabetic stages. Methods Fourty Wistar rats were randomly divided into four groups: 1-week normal control group(NC 1 group; n=6), 4-week normal control group (NC2 group;n=6), 1- week diabetes mellitus group (DM 1 group; n = 14)and 4-week diabetes mellitus group (DM2 group ; n = 14). One week and four weeks after the STZ injection, gastric emptying measured by intragastric administration of phenol red;serum leptin concentrations were measured with that of radioimmunoassay; expression of OB-Rb mRNA in hypothalamus was detected with semi-quantitative RT-PCR. Results 1-week after the STZ injection, the expression of serum leptin and OB-Rb mRNA in hypothalamus of DM1 group was decreased signifieantly compared with that of the control (P ＜0.05;P ＜ 0.05) ;DM1 group showed significantly accelerated rates of gastric emptying of the fluid compared with that of the NC1 group (P ＜ 0.01). 4-week after the STZ injection, serum leptin and gastric emptying of the DM2 group decreased significantly compared with that of the NC2 group(P ＜0.05; P ＜ 0.01). Oppositely, the expression of OB-Rb mRNA in the hypothalamus of DM2 group increased significantly(P＜0.05). Conclusion The decreased serum leptin and OB-Rb in the hypothalamua on the short-term hyperglycemia may participate in the rapid gastric emptying and increase ingestion reaction, which can maintain energy balance of the body. The high expression of OB-Rb in the hypothalamus may be a protective mechanism that it could increase leptin sensitivity to inhibit gastric emptying on the long-term hyperglycemia.