Aim To explore the effects of aerobic exercise on 6-minute walk distances (6MWD), the lower limb motor function and serum chemerin in patients with chronic hemiparesis after stroke. Methods 108 patients with chronic hemiparesis after stroke were randomly divided into three groups:drug treatment group, drug treatment combined with aerobic exercise treatment group and aerobic exercise treatment group. Drug treatment group and drug treatment combined with aerobic exercise treatment group were given conventional medical therapy. The patients in drug treatment combined with aerobic exercise treatment group and aerobic exercise treatment group received regulear aerobic exercise using power bicycle each for 30 min, 3 times a week in 3 months. 6MWD, simplified Fugl-Meyer lower limb motor function assessment (FMA), blood pressure, body mass and height were recorded, serum chemerin, C-reactive protein (CRP), homocysteine, biochemistry were determined before and after the 3 months therapies. Results There were no significant difference among the three groups before treatment for 6MWD, FMA scores, serum chemerin, CRP, homocysteine, fasting blood glucose, blood lipids, blood pressure, body mass and body mass index(P>0.05 ). After 3 months treatment, 6MWD, FMA scores in drug treatment combined with aerobic exercise treatment group were significantly increased(P<0.01), serum chemerin, CRP, homocysteine, fasting blood glucose, total cholesterol, low density lipoprotein cholesterol(LDLC), systolic blood pressure and body mass in drug treatment combined with aerobic exercise treatment group were significantly decreased (P<0.05), 6MWD, FMA scores in aerobic exercise treatment group were significantly increased(P<0.01), serum chemerin, CRP, homocysteine, fasting blood glucose, total cholesterol, LDLC, systolic blood pressure and body mass in aerobic exercise treatment group were significantly decreased (P<0.05), 6MWD, FMA scores in drug treatment combined with aerobic exercise treatment group were significantly increased than those in drug treatment group after treatment, and CRP, fasting blood glucose and systolic blood pressure in drug treatment combined with aerobic exercise treatment group were significantly decreased than those in drug treatment group after treatment (P<0.05). Before treatment, chemerin was negatively related with 6MWD(r=-0.279, P<0.01). Multiple stepwise regression analysis revealed that chemerin levels was independently associated with 6MWD (P<0.05). Conclusion Aerobic exercise significantly increase 6MWD, FMA scores, reduce serum chemerin, CRP, homocysteine, fasting blood glucose, blood lipids and blood pressure in patients with chronic hemiparesis after stroke, thereby improve quality of life, inflammatory state and the risk factors related to cardiocerebral vascular diseases in patients with chronic hemiparesis after stroke.