Textile printing and dy eing wastewater is treated by improved hydrolytic acidification -biological contact oxidation process.Some steps such as pre-aeration, return sludge, graded sedimentatio n and so on have been taken.The CODCr removal rate is about 95%, the efficiency on decolourization can reach 97 %.The end effluent quality meets the requirement of Grade 1, Discharge Standard for waste water in Guangzhou city.The running results show that it is of advantage for less residual sludge, stronger impactload endurance and higher removal efficiency on refractory organisms, and it has applicability in the treatment of tex tile printing and dyeing wastewater.