Abstract: In this study,the characteristics of anaerobic granules degrading pentachlorophenol(PCP) were investigated in a pilot-scale upflow anaerobic sludge blanket (UASB) reactor at (35±1)℃.Experimental results demonstrate:①When brewery waste-degrading granules obtained from a full-scale UASB reactor treating brewery wastewater were used as seed,the start-up process was completed within 120 d,with influent COD 2 500～2 800 mg/L,a hydraulic retention time 20～24 h and influent PCP 1.0～8.0 mg/L.The COD and PCP removal rates were 86% and 94% respectively.②The determinations of cholrophenols in effluent and reactor suggest that the PCP degrading granules dechlorinated PCP primarily at the meta-position,then at the ortho-position and the para-position,and a part of intermediates were finally to CH₄ and CO₂.