Abstract: Methods of sludge pretreatment and substrate mass concentration influencing fermentation of poultry dung wastewater are investigated in this research.The anaerobic conditions are as follows: temperature is 36 ℃,pH is 5.0,and rice bran fluid is added to increase w(C)/w(N) of wastewater.Meanwhile,terminal product of liquid phase and removal rate of COD of fermentation liquor are also analyzed.Results show that the best method of sludge pretreatment is heat treatment(at 100 ℃ for 15 minutes);the production of cumulative biogas and hydrogen are 1 781 mL and 1 082.8 mL,2.52 and 5.85 times untreated group,respectively.The optimum mass concentration of poultry dung wastewater is 10 218 mg/L with hydrogen yield as 185.1 mL/g.At the end of fermentation,the products of liquid phase are organic acids such as acetic acid and butyric acid.The removal of COD varies with substrate concentration,which reaches 26.9% at the mass concentration of 10 218 mg/L.