In this study, we attempted to analyze removal efficiency of odorous compounds emitted from Grit chamber and night soil treatment facility using biofilter with microbial catalyst. Air dilution method was used for mixed odor gases analysis. UV-vis spectrophotometer for ammonia and Hydrogen sulfide, Methyl mercaptan, Dimethyl sulfide, Dimethyl disulfide were measured using GC/PFPD. Sample gases were collected at the inlet and outlet of biofilter. The analysis result showed that average concentration of major odorous compounds were ammonia with 5,100 ppb and hydrogen sulfide with 797 ppb from grit chamber and ammonia with 1,407 ppb and hydrogen sulfide with 2,475 ppb from night soil treatment facility. Hydrogen sulfide was the most influential compound of malodor based on odor quotient index. The average dilution threshold of odor was 923 at grit-chamber and 1,267 at night soil treatment facility. The removal efficiency of odorous compounds from sewage treatment facility were more than 94% using polyurethane foam biofilter within empty bed contact time 3sec. The emitted concentration to the atmosphere was satisfied with the criterion of the offensive odor control law.