An advanced sludge reduction process, i.e. sludge reduction and phosphorous removal process, was developed. The results show that excellent sludge reduction and biological phosphorous removal can be achieved perfectly in this system. When chemical oxygen demand /)(COD) is 332 -420 mg/L, concentration of ammonia p(NH3-N) is 30 -40 mg/L and concentration of total phosphorous p(TP) is 6.0 -9.0 mg/L in influent, the system still ensures p(COD)~23 mg/L, p(NH:N)~3.2 mg/L and p(TP)~0.72 mg/L in effluent. Besides, when the concentration of dissolved oxygen p(DO) is around 1.0 mg/L, sludge production is less than 0. 140 g with the consumption of 1 g COD, and the phosphorous removal exceeds 91%. Also, 48.4% of total nitrogen is removed by simultaneous nitrification and denitrification.