Removal effect of Cl adophora fracta (Dillw. ) Kuetz. on benzene, toluene, and xylene is studied using L9 (34 ) orthogonal design. Results show that the removal rates of benzene, toluene, and xylene are 46.6 %, 13. 6 %, and 7. 4 %, respectively. The effect of the different processing conditions of C. fracta on benzene removal rate is analyzed. Analysis indicates that the temperature is the primary factor of the removing effect and the exposure time and algal weight take the second and third places. For the removal of the toluene, the main factor is the exposure time and the next is the algal weight and temperature. But for xylene,the algae weight is the most important factor .