Background and Objectives : Endothelial dysfunction is an early change in the process of atherosclerosis. To evaluate endothelial function, it needs expensive and specialized medical device like high resolution vascular ultrasound. Therefore, we sought to compare this atherosclerotic parameter of endothelial function using inexpensive and simple method of peripheral pulse arrival time (PPAT) measurement. Materials and Methods : Before and after meals, we measured PPAT and flow-mediated vasodilation (FMD). Resting PPAT in both arms were measured with PPAT device that was designed by the authors. Hyperemic effect was tested in both arms after raising blood presssure cuff to 250 mmHg for 5 minutes by blood pressure cuff and then cuff was released to 0 mmHg. PPAT was measured within first 1 minutes to see the hyperemic response. FMD was measured in the same process by 7 MHz high resolution ultrasound in the left brachial artery. Percent change was calculated from the baseline value and that of hyperemic response. Results : PPAT change with low-fat diet was not different (3.8% vs 4.7%, p=63). In high-fat diet, PPAT tended to be short without statistical significance(4.8% vs 2.7%, p=0.16). The change of FMD after low-fat diet was not different(11.7% vs 11.4%, p=0.58). In high-fat diet, there was a significant differences in FMD(11.4% vs 6.5%, p<0.001). Conclusion : The PPAT measurement could be a method for evaluating endothelial function, but less sensitive than flow-mediated vasodilation.