Abstract： Objective To compare the efficacy of uniform multi-drug therapy (UMDT) versus routine multi-drug therapy (RMDT) for the treatment of multi-bacillary (MB) leprosy patients based on bacterial index changes and frequencies of leprosy reaction.Methods This study recruited newly diagnosed leprosy patients after taking informed consent in three districts of Guizhou province as well as in one district of Yunnan province from November 2003 to June 2005.The patients received 6-month UMDT or 2-year RMDT.Clinical follow up and bacterial reexamination were carried out once a year.Changes of bacterial index (BI) and frequencies of leprosy reaction were compared between the patients receiving RMDT and UMDT.Results A total of 166 patients received UMDT and 170 received RMDT in this study.Among the UMDT-treated patients,114 were skin smear positive,and 83 had been followed up for 42 months; of the RMDT-treated patients,149 underwent all the bacterial examinations during a 48-month follow up.The mean bacterial index decreased from 2.84 before treatment to 0.33 at the end of the 42-month follow up in the 83 patients,and from 2.55 to 0.26 at the end of the 48-month follow up in the 149 patients,with no significant difference in the changes of bacterial index between the two groups (t =0.77,P ＞ 0.05).Bacterial index became negative in 73.5％ (61/83) of the UMDT-treated patients and in 77.2％ (115/149) of the RMDT-treated patients (x2 =0.40,P＞ 0.05)at the end of follow up.During the follow up peroid,the incidence of type Ⅰ leprosy reaction was 14.6％ (13/89) in the UMDT group,significantly higher than that in the RMDT group (3.4％ (5/149),x2 =10.08,P＜ 0.01 ).Conclusions There is no significant difference in mean bacterial index changes and bacterial clearance rate during the follow up peroid between UMDT- and RMDT-treated patients.The incidence of type Ⅰ leprosy reaction is higher in the UMDT group than in the RMDT group,and further investigation is needed to clarify the mechanisms underlying the phenomenon.