The feasibility of using Micrococcus sp. to bioaugment a sequencing batch reactor (SBR) for degrading di-n-butyl phthalate (DBP) was investigated. Terminal restriction fragment length polymorphisms (T-RFLP) was used to analyze the changes in sludge microbial community. The experimental results showed that for the bioaugmented reactor, the removal efficiency of DBP degradation of DBP was about 85% as compared with 25% of the control reactor when initial DBP concentration was 100 mg/L. The bioaugmentation not only enhanced the removal efficiency of target compound, but shortened the start-up time of the reactor. The kinetics of DBP degradation conformed to the first-order model in both reactors. The T-RFLP analysis indicated the bacterial community changes of the acclimated activated sludge and the introduced Micrococcus sp. during the operational process.