There are no objective sonographic findings of diabetic nephropathy reported in the past. After Doppler sonography we were able to predict the vascular resistance of peripheral organs by calculating the resistive index of the doppler waveform. This study was undertaken to determine the role of the resistive index in the evaluation of diabetic kidndys. The resistive Index of 20 healthy volunteers and 30 diabetics were analyzed and correlated with clinical laboratory late including proteinura, BUN, creatinine, duration of diabetes mellitus history and fasting blood glucose level in diabetics. Resistive index of diabetics was significantly higher than normal volunteers and well correlate with serum creatinine, fasting blood glucose levels and duration of diabetees history. The resistive index of the kidndey in diabetics is well correlated with clinical laboratory data. Therefore, we can carefully predict impending diabetic nephropathy by using the resistive index.