Abstract : In order to study the effect of Nano–particles on the low organic waste activated sludge fermentation performance. The WAS were fermented in the nanometer CuO (Nano–CuO) and nanometer ZnO (Nano–ZnO) fermentation systems. The results showed that the hydrolytic acidizing property of Nano--ZnO fermentation system was significantly higher than Nano--CuO fermentation system. Protease increased with the addition of Nano--ZnO and Nano--CuO, and the maximal value was 25.15 EU/mg VSS (N