Abstract: In order to investigate the feasibility of biofiltration elimination of malodor from oil refining wastewater treatment plant,two biofilters in series packed with a mixture of compost, bark and lava,which each consisted of three segments were used in this study. The removal of main contaminants, the influence of shock load and the variation of nutrients in the packing material were investigated. At empty bed residence time (EBRT) of 66 s, inlet concentration of non-methane hydrocarbon (NMHC), benzene, toluene and xylene in the range of 5. 1—1081. 8 mg·m-3, 0. 1—328. 8 mg·m-3, 0. 2—91. 8 mg·m-3 and 0. 2—48. 2 mg·m-3 respectively, the respective average removal efficiency values were 79. 7%, 98. 9%, 98. 8% and 99. 6%. The biofilter had favorable ability against shock load due to sudden variation of concentration. The leachate from the biofilter was circulated back to the packing bed of biofilter. The malodor from oil refining wastewater treatment plant could be successfully eliminated in this biofilter.