OBJECTIVE： To observe clinical efficacy and safety of mesalazine combined with Kangfuxin solution retention enema in the treatment of active ulcerative colitis （UC）. METHODS： A total of 120 patients diagnosed as active UC selected from gastroenterology department of our hospital during Mar. 2012 to Aug. 2014 were divided into observation group and control group according to random number table， with 60 cases in each group. Both groups received conventional treatment of active UC. Control group was additionally given Mesalazine enteric coated tablets 1 g， tid， on the basis of routine treatment. Observation group was additionally given Kangfuxin solution 30 mL diluted with normal saline 150 mL for enema， qd， on the basis of control group. Both groups were treated for 30 d. The serum levels of TNF-α， IL-1， IL-8， IL-10， SOD， NO and LPO were observed in 2 groups before and after treatment； clinical efficacies， recurrence rates， colonoscopy efficacies and the occurrence of ADR were compared between 2 groups. RESULTS： Before treatment， there was no statistical significance in the serum levels of TNF-α， IL-1， IL-8， IL-10， SOD， NO or LPO between 2 groups （P＞0.05）. After treatment， the serum levels of TNF-α， IL-1， IL-8， NO and LPO in 2 groups were decreased significantly， while the serum levels of IL-10 and SOD were increased significantly； the serum levels of TNF-α， IL-1， IL-8， NO and LPO in observation group were significantly lower than control group， while the serum levels of IL-10 and SOD were significantly higher than control group， with statistical significance （P＜0.05）. Clinical response rate， recurrence rate and colonoscopy response rate of observation group were 83.3％， 11.7％ and 88.3％， which were significantly better than 66.7％， 30.0％， 70.0％ of control group， with statistical significance （P＜0.05）. There was no statistical significance in the incidence of ADR between 2 groups （P＞0.05）. CONCLUSIONS： Mesalazine combined with Kangfuxin solution can effectively alleviate inflammatory reaction in patients with active UC， and reduce oxygen free radical damage with good safety.