Abstract: Objective To observe the effect of monocyte chemoattractant protein-1（MCP-1） on apoptosis of pancreatic β-cells and study its possible mechanism. Methods Forty-eight hours after in vitro cultured rat pancreatic β cell line INS-1E was stimulated with 1ng/ml MCP-1,expression levels of amylin mRNA and protein in rat pancreatic β cells were measured by real-time PCR and Western blot,respectively.Apoptosis of rat pancreatic β cells was detected by flow cytometry.Forty-eight hours after in vitro cultured rat pancreatic β cells transfected with amylin SiRNA were stimulated again with 1ng/ml MCP-1,their apoptosis was detected by flow cytometry. Results The expression levels of amylin mRNA and protein in INS-1E cells were significantly higher after MCP-1 stimulation than before MCP-1 stimulation（P＜0.05） and the apoptosis of INS-1E cells occurred.However,the apoptosis rate of INS-1E cells was lower when the expression level of amylin mRNA in INS-1E cells was stimulated with MCP-1 and transfected with amylin mRNA than when the expression level of amylin mRNA in INS-1E cells was only stimulated with MCP-1（P＜0.05）. Conclusion MCP-1 can regulate the apoptosis of rat pancreatic β cells by promoting the expression of amylin,thus influencing the metabolism blood sugar.