nowadays many sites are contaminated by mixed wastes of organics. As mixed wastes, such petroleum/gasoline compounds as benzene, toluene, ethylbenzene, and three isomers of xylene (BTEX) and total petroleum hydrocarbons (TPH) and such chlorinated compounds as trichloroethylene (TCE) are among the most frequently found subsurface contaminants. In this study, one indigenous microorganism isolated from a heavily oil-contaminated site in Xiamen, China was used to remove mixtures of BTEX, TPH, and TCE under different environmental conditions [temperature, pH, dissolved oxygen (DO)], from the artificially contaminated water. In general, the higher mixture removal efficiency occurred at the DO concentration of 7-8 mg/L and 25°C, regardless of pH. Furthermore, mixtures were shown with the higher bioremoval efficiencies at the neutral or slightly alkaline condition. At the higher DO concentration, the highest bioremoval of BTEX occurred at 25°C, while it occurred at the higher temperature (35°C) at the lower DO concentration. On the other hand, the higher TPH bioremoval occurred at 25°C, while the higher TCE bioremoval occurred at 35°C. These results would help improve the applicability of bioremediation technology to the mixed wastes contaminated sites.