Abstract： Objective To explore the effect of ghrelin on insulin release of mouse pancreatic islet β-cell line（NIT-1 cells） and its probable mechanism.Methods NIT-1 cells were incubated in high-glucose DMEM with ghrelin.Then,the media was sampled for the assay of insulin by RIA.The（mRNA） expressions of glucose transporter 2（GluT2）,pancreatic-duodenal homeobox-1（PDX-1）,inwardly rectifying potassium channel with two transmembrane regions（Kir6.2） and sulphonylurea receptor 1（SUR-1） in the cells were detected by using RT-PCR.The cell proliferation was determined by MTT assay.Results（1） 10-9mol/L to 10-7mol/L of ghrelin inhibited dose-dependently the high-glucose challenged insulin release of the NIT-1 cells.（2） The mRNA expression of Kir6.2,but not GluT2,PDX-1and SUR-1,was down-regulated by 10-7mol/L of ghrelin.（3） Ghrelin had no effect on proliferation of the cells.Conclusions Ghrelin inhibits high-glucose induced insulin secretion of the islet β-cells.This effect may be secondary to the down-regulation for the expression of Kir6.2,（a component） of ATP-sensitive potassium channel.