The performance of a swine wastewater treatment process composed of an upflow sedimentation tank for pretreatment, an UASB reactor, and a trickling filter for post treatment was examined using a pilot plant. The UASB reactor has a volume of 1 m3 (0.6 m diameter × 3.5 m height), 48 hrs for hydraulic retention time (HRT) and 25°C in reactor temperature. The trickling filter was 0.6 m in diameter and 2 m in height. The operation of the pilot plant was carried out from February 1998 to July 1998 with supplying 0.5 m3/day wastewater discharged from a swine barn. Water quality of influent was 5, 000-30, 000 mg/l for suspended solids, 10, 000-30, 000 mg/I for CODCr, 3, 000-10, 000 mg/l for BOD, 200-400 mg/l for total phosphorus, and 600-1, 500 mg/l for total nitrogen. Effluent water quality was 200-600 mg/l for suspended solid, 500-2000 mg/l for CODCr, 100-300 mg/l for BOD, 80-100 mg/l for total phosphorus and 400-600 mg/l for total nitrogen. The removal efficiency of BOD was 80-95% by the UASB reactor and 97-99% by the total process. Methane gas production was about 1 m3/m3-reactor·day during the initial stage and declined gradually with the dropping of influent BOD. Sulfide contained in biogas was removed from 3, 000 ppm to less than 2 ppm by a packed column type H2S remover in which the effluent was spreaded continuously.