Abstract: Objective To study the safety reference value of blood glucose for preventing diabetic nephropathy.Methods A total of 311 diabetic patients was collected and divided into two groups,diabetic nephropathy group and nondiabetic nephropathy group,and the fasting blood glucose was then detected.Accor ding to the values of blood glucose,the subjects were divided eaqually into 5 levels.Ordinal regression analysis were used to get the cumulative probabilities and regression coefficents of suffering diabetic nephropathy or not.Receiver operating characteristic(ROC)method were used to analyze the sensitivity and false positive rate,and diagrams of curves of ROC were constructed and drawed to get the safety reference value of blood glucose for preventing diabetic nephropathy.The negatively predictive value for a diabetic without suffering from diabetic nephropathy was calculated accrding to the safety reference value.Results The safety reference value of blood glucose for preventing diabetic nephropathy is 8.4 mmol/L,and the 95% confidence interval is between 8.1 mmol/L and 8.8 mmol/L.If the blood glucose could be controled in this range,the possibility or the negativ ely predictive value of a diabetic without suffering diabetic nephropathy is between 71% and 62%.Conclusion The safety reference value of blood glucose and the negatively predictive value of a diabetic suffering diabetic nephropathy obtained by establishing ROC curve equations can be used to control the blood glucose of diabetic and make a prog nosticevaluation for preventing diabetic nephropathy complication.