Submerged Aerobic Biofilm Reactor(SABR) with series was investigated for wastewater treatment of the Pusan Janglim wastewater plants. SABR has obtained high SS removal efficiency which also showed flexible to load change. SABR has gained avg. organic removal rate 12.2gSCOD/㎡·d (1.4㎏TCOD/㎥·d) in stage 1+2. Nitrification was mainly accomplished at stage 1, 2 in that nitrification rate was avg. 2.6gNH₄-N/ ㎡·d (0.2㎏NH₄-N/㎥·d). This system also sustained high VSS conc. 14,111㎎VSS/l (about 177gVSS/㎡·d) in stage 1, as a results, substrate(ogranics, ammonia)removal was completed in stage 1, 2. There was also observed that nitrification rate was influenced by pH change. Those results suggest that SABR combined sand filter applicable in small-scale treatment plants without secondary clarifier.