Objective To study the effect of ethanol extract of propolis （EEP） and exercise on the immune function of obese people after exercise.Methods One hundred men were randomly assigned to the EEP group （n=50） and the placebo group （n=50）. The subjects in both groups exercised on a treadmill at an exercise intensity of 65% VO_2max. They exercised for 1 h a day and 5 times a week for 8 weeks. Participants in the EEP group took 1 EEP capsule （containing 100 mg EEP） once a day， and participants in the placebo group took 1 capsule that looked similar to the EEP capsule every day， which continued for 8 weeks. Then the NK cell activity， inflammatory factors ［（tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β） and IL-10）］ levels and the proportion of lymphocytes （T cells， B cells and NK cells） were detected.Results Compared with the placebo group， the NK cell activity of the EEP group significantly increased （50.14%±8.86% vs 55.73%±7.85%， P=0.011）. Compared with the placebo group， serum TNF-α （893.46±177.32 pg/mL vs 637.53±152.35 pg/mL， P=0.014） and IL-1β （122.14±18.57 pg/mL vs 99.95±16.46 pg/mL， P<0.001） levels of the EEP group decreased significantly， and IL-10 （7.16±1.58 pg/mL vs 10.45±1.78 pg/mL， P=0.008） increased significantly. There was no significant change in the percentages of T cells， B cells and NK cells at baseline and after 8 weeks in the two groups （P>0.05）.Conclusion Taking EEP during exercise can help stimulate the activation of NK cells by improving the immune function.