Background: Regular exercise has been well known to prevent of diabetes and cardiovascular diseases in obesity, but the underlying mechanisms are not completing understood. Inflammatory marker such as plasma high sensitivity C-reactive protein (hs-CRP) is associated with an increased risk of developing diabetes and coronary artery diseases. Thought previous studies reported that physical activity and cardiorespiratory fitness are associated with hs-CRP based on cross-sectional study, there is few date to the impact of hs-CRP after regular aerobic exercise training in obesity. Therefore, we examined the effects of exercise training on hs-CRP in obesity. Methods: The 50 obese (49.6짹6.7yrs) were randomly assigned into the exercise training group (n=23, BMI 28.6짹2.3) or the control group (n=27, BMI 27.4짹 2.5) who given general information about health diet and exercise. Exercise group was instructed to continue prescribed exercise at 50 – 80% of maximal heart rate for 40 to 60 minutes a day, 5 days per week for 3 months. Results: There were no differences between groups at baseline data. After 3 months, the BMI (28.6짹2.3 to 26.4짹2.1, p<0.001) %BF (30.5짹4.9 to 25.8짹4.6, p<0.001), VO2peak (30.3짹5.1ml/kg/min to 37.1짹6.9, p<0.001), LDL-C (151.3짹34.9mg/dl to 116.7짹27.8, p<0.001) and log hs-CRP (0.75짹0.39mg/dl to 0.55짹0.29, p=0.007) were significantly improved in exercise group, but no significantly improved in control group (BMI; 27.4짹2.5 to 27.4짹2.6, p=0.921) %BF (28.3짹3.9 to 28.8짹4.2, p=0.390), VO2peak (30.9짹5.1 to 30.0짹4.8, p=0.024), and log hs-CRP (0.58짹0.33 to 0.66짹0.38, p=0.183). VO2peak changes were associated with changes in CRP (r=-0.46, p<0.001). Conclusions: Regular exercise training was decreased plasma hs-CRP in obese, which could contribute to decrease risk of cardiovascular and diabetes in obesity.