Burkholderia cepacia DA2, isolated from marine sediment of the South China Sea, is capable of utilizing dimethyl phthalate (DMP) as the sole source of carbon and energy. During the transformation of DMP in batch culture, its corresponding degradation intermediates were identified as monomethyl phthalate (MMP) and phthalate acid (PA) sequentially over the time of incubation. The biodegradation biochemical pathway of DMP was DMP to MMP and then to PA before mineralization. Degradation of DMP by B. cepacia DA2 was also dependent upon DMP-induction, and the initial concentrations of DMP affected the degradation rate. Degradation kinetics fit well with the modified Gompertz model. The optimum pH and salinity was 6.0 and < 5 per thousand, respectively, for DMP degradation by B. cepacia DA2. This study showed that the indigenous microorganisms of the deep-ocean sediments are capable of DMP degradation completely.