Abstract: In order to study the effect of different salinity on the sludge bulking, a continuous experiment was carried out to treat wastewater containing saline by using sequencing batch reactor(SBR). The effect of changes of NaCl, Na2SO4 and Na3PO4 salinity on the removal efficiency of pollutant and settleability of activated sludge were investigated when sodium acetate was used as carbon source. The results showed that under the condition of dissolved oxygen (DO) of 3mg/L, sludge volume index(SVI) was dropped from 135mL/g to 71mL/g, and removal efficiency of total nitrogen(TN) was dropped from 80% to 60% and extracellular polymeric substance(EPS) was increased from 521mg/L to 917mg/L, and the sludge performed a favorable settleability when NaCl salinity was increased gradually from 0 to 30g/L. When the Na2SO4 salinity was increased gradually from 0 to 30g/L, SVI was dropped from 135mL/g to 73mL/g, and removal efficiency of TN was dropped from 81% to 60% and EPS was increased from 523mg/L to 896mg/L. However, when Na3PO4 salinity was increased gradually from 0 to 8g/L, SVI was increased from 135mL/g to 198mL/g, and removal efficiency of TN was dropped from 80% to 60% and EPS was increased from 549mg/L to 674mg/L. And furthermore, sludge bulking was produced. When the salinity of NaCl and Na2SO4 was increased, removal efficiency of TN was decreased, sludge settleability and EPS mass concentration was increased. When the salinity of Na3PO4 increased, sludge settleability and removal efficiency of TN were decreased, EPS mass concentration was increased. However, with the decreasing salinity of NaCl (30~0g/L), Na2SO4 (30~0g/L) and Na3PO4 (8~0g/L), SVI was increased from 71mL/g to 298mL/g, 73mL/g to 291mL/g and 198mL/g to 241mL/g, respectively, and removal efficiency of TN was dropped from 62% to 43%, 65% to 44% and 60% to 35%, respectively, and EPS was increased from 917mg/L to 1092mg/L, 896mg/L to 1078mg/L and 674mg/L to 759mg/L, respectively. After salinity of NaCl, Na2SO4 and Na3PO4 reduced from high value to low value, sludge settleability and removal efficiency of TN decreased, and EPS mass concentration continued to increase. Sludge bulking was produced after the salinity was reduced. （英文未粘）