The purpose of this study is to observe clinically the effects of red onion prescription on type 2 diabetes. The subject of this study were middle-aged people. We measured clinically physiological index, body composition, radial arterial pulse wave before taking medicine and after taking medicine for 4 month (the prescription of red onion). The study results were as follows. In physiological Index, diastolic blood pressure(mmHg)(p<0.001), Fasting blood glucose(mg/dL)(p=0.001), and HbA1c(%)(p<0.001) were decreased significantly after taking medicine. In body Composition, waist-hip ratio(p=0.031), body fat percentage(p=0.006), fat mass(kg)(p=0.005), and muscle mass(kg)(p=0.001) were decreased significantly after taking medicine. Blood Circulation Index, ECO(L/min)(p=0.038) and ECI($L/min/m^2$)(p=0.007) were increased significantly after taking medicine, ECR($dyne^*sec^*cm^{-5}$)(p=0.002), and ECRI($dyne^*sec/cm$)(p=0.001) were decreased significantly after taking medicine for 4 month. The prescription of red onion was showed significant change in physiological index, character of body composition, blood circulation index. Based on this result, it is considered that red onion prescription has the positive effects on type 2 diabetes and blood circulation clinically. In the future, diversified studies on the effects of red onion prescription are needed.