Abstract: Waste activated alkaline hydrolysis can produce short- chain fatty acids that can be applied into the sewage nitrogen and phosphorus removal process; however, it also causes the deterioration of the dewaterability. This experiment investigated the anaerobic hydrolysis process and dewaterability of waste activated sludge in 20 days under various total suspended solids (TSS) and temperatures at pH = 10.Conclusionsare as follows: at 25 ℃, sludge dewaterability deteriorated with the increase of TSS and then changed little. SCOD kept stable after progressively increasing. At 35 ℃, sludge dewaterability deteriorated with the increase of TSS first, and then increased slightly. The changes of SCOD brought into correspondence with SCOD at 25 ℃. SCOD and normalized CST had a significant positive correlation. Higher temperatures caused higher leaching SCOD and slightly worse dewaterability. TSS influenced the dewaterability of sludge more significantly than temperature.