This study assesses the recital of fixed bed reactors in anaerobic treatment of sago industry wastewater using Effective Microorganism. A laboratory scales Up flow Anaerobic fixed bed reactor, having a working effective volume of about 13. L was operated and Polypropylene rings were used as packing media. The initial Hydraulic Retention Time range was about 0.6 days and further increased. Various effluent characteristics ranges of COD concentration, Total Suspended Solids, VFA, and biogas production were studied until the attainment of steady state. The Hydraulic Retention Time of a sago wastewater was 3.0, 1.50, 1.00, 0.75, 0.60 days. The maximum COD removal efficiency of 83% was attained at a prefixed flow rate of 0.18 l/day with the average COD of 5320 mg/l at 3.0 days HRT. It was accomplished that the influence of COD reduction was increase to increases the HRT. The gas production was increased with increased OLR. The maximum gas production of 0.255 m3/kg COD in fixed bed reactor in the presence of effective microorganisms was obtained.