Recently, the prevalence rate of diabetes in Korea has been increasing rapidly due to high growth of economy and changes in dietary lifestyle. Vascular complication is one of diabetic complications which have frequently occurred by obesity, hyperglycemia and impaired glucose metabolism. Photoplethysmogram(PPG) measured from finger and toe is very useful for evaluation of vascular aging and sclerosis level since the PPG signal represents characteristics of peripheral vascular. Several researchers have reported that second derivative of the finger PPG waveform was useful to evaluate vascular compliance and developed various analysis methods for vascular compliance. However, peripheral vascular compliance study for diabetic patient was never evaluated by using second derivative of PPG. Therefore, we aimed to objectively compare and to assess normal(n=50) and diabetic(n=50) groups vascular compliance using the second derivative of PPG waveform in this study. The evaluated factors of the second derivative of PPG are 'a', 'b', 'c', 'd', 'e' and b/a represents vascular compliance. This study found out that when vascular compliance is decreased, the absolute value of b/a is decreased. The average vascular compliance of 50 diabetic patients with neuropathy, -1.09±0.14, is statistically lower than the normal group, -0.81±0.09 (p<0.05). In conclusion, we suggest an objective evaluation of peripheral vascular compliance for diabetic patients and prevention of vascular complication.