This study aims to maximize the performance of sludge fermentation tank by improving the agitation system under aerobic condition. Sewage sluge of company B in G city was used for test of pilot scale as 1 ton/day. For the analysis of sludge properties, 10 toxic substances such as arsenic and cadmium were analyzed as the results of non detection concentrations. Oil content, water content and organic content were reported as 0.33 %, 70.8 % and 92.8 %, respectively. The sludge was added at 29.0 tons / month for 6 months, resulting in an average of about 27.7 tons of sludge being lost by the fermentation. Thus, 1.31 ton of sludge was discharged from the tank, resulting in an average sludge reduction efficiency of 95.5 %. To investigate organic matters during fermentation, TOC concentrations were compared three times before and after fermentation. First sludge sample sampled within one month of operation reduced TOC by approximately 1.0 % from 41.0 % to 40.5 %. This resulted from the abnormal conditions due to the stabilization of the tank. After 45 days and 60 days of the operation, the TOC for the 2^nd and 3^rd tests were reduced to 57.0 % and 49.2 %. By using the applied factors in this study, the air flow was calculated as 1,400㎥/day for 1ton/day pilot scale.