Recently, biofilm reactors are considered as efficient wastewater treatment system in rural areas, because of characteristics of easy operation and economic feasibility. In order to select the most efficient media, an experimental apparatus with five different media was designed, installed and examined. The media used in this study were zeolite, artificial sponge gourd, absorbent biofilter, non-woven fabric and charcoal. With only one month investigation, all five media showed high removal efficiencies of BOD.