Objective Although metformin regulates blood glucose level primarily by improving insulin sensitivity, there is evidence that it also preserve insulin secretion of pancreatic β-cells from glucotoxicity or lipotoxicity directly. However, the exact mechanism is not clarified yet. Previously we showed that inhibition of CD36, a fatty acid transporter, prevents glucotoxicity and ameliorate high level of glucose induced β- cell dysfunction. The aims of this study are to investigate the beneficial effect of metformin on β-cell function and whether if this effect is associated with change of CD36. Methods We compare insulin expression, glucose stimulated insulin secretion (GSIS), ROS and change of CD36 expression under high glucose (HG, 30 mM) condition with normal glucose (NG, 5.6 mM) in INS-1 cells. We also assessed aforementioned factors in condition with metformin for evaluation of glucotoxicity prevention effect. Results CD36 expression was increased with 12-hour HG exposure in INS-1 cells, which was suppressed by metformin. Insulin and PDX-1 mRNA expression were decreased and GSIS was completely disappeared by 3-day of HG, which was restored partly by metformin. Also Metformin partially recovered elevated ROS by 3-day HG. Conclusion Metformin suppresses the CD36 expression elevated by HG, which may be associated with glucotoxicity. These results suggest that metformin prevents CD36 related glucotoxicity in INS-1 cells and further in vivo studies are needed.