Abstract： Objective To determine the primary control factors of nucleotides metabolisms on insulin secretion.Methods NMRI mice isolated islets were used to investigate the amount of insulin secretion and the changes of ATP,ADP,GTP,GDP and UTP in islets when the activity of K + ATP channel was eliminated by diazoxide.Results The above assays demonstrated that insulin secretion increased with the rise of glucose concentration.In the same time,ratio of ATP/ADP,GTP/GDP and level of UTP increased,too.All three indexes correlated with the insulin secretion very well respectively,but only ratio of ATP/ADP can control insulin secretion directly in common influence.Conclusion Our findings suggest that there is the second control site in islets when glucose induces insulin secretion and ATP/ADP ratio is only key factor in this mechanism.