Abstract: Objective To investigate the efficacy of etimicin combined with levofloxacinin the treatment of Methicillin-resistant Staphylococcus aureus (MRSA) infections in diabetic foot and the polymorphism of capsular polysaccharide synthesis gene. Methods A total of 78 diabetic patients with MRSA infections in the Affiliated Hospital of Hangzhou Normal University between October,2012 and October,2014 were randomly divided into control group (n=39) and experimental group (n=39).The patients of the control group,20 males and 19 females,aged 30-72 years with an average age of (47.8±18.2) years,received levofloxacin treatment;while the patients of the experimental group,20 males and 19 females,aged 28-75 years with an average age of (49.1±19.5) years,received etimicin combined with levofloxacin treatment.The course was 4 weeks in both groups.The efficacy was evaluated with Wagner grading method.The treatment efficiency was compared between the two groups,and the polymorphism of capsular polysaccharide synthesis gene was studied. Results The clinical overall response rate in the experimental was significantly higher (P<0.05) than the in the control group;On d28,the positive rate of Staphylococcus aureus infection in the wound in experimental group was significantly lower than that in the control group (P<0.05);PCR analysis showed that the type 5 and 8 capsular polysaccharide synthesis gene were mainly the disease gene (61.5%). Conclusion Etimicin combined with levofloxacin has obviously therapeutic effect on MRSA infections in diabetic foot,which will improve the effective rate.The type 5 and 8 capsular polysaccharide synthesis gene are mainly the disease gene.