Abstract: This paper discussed the influences of H 2O 2 usage, temperature, reaction time, O 2 pressure on surface activity, content of acid soluble lignin of oxidized wheat straw alkaline lignin.The orders of four factors were all listed as H 2O 2 usage, temperature, reaction time, O 2 pressure. While 20% H 2O 2 applied, the wheat straw alkaline lignin oxidized at optimized conditions as: temperature of 90 ℃, reaction time of 0.5 h, O 2 pressure of 0.6 MPa had the best surface activity. Oxidized on reaction conditions with H 2 O 2 usage of 20%, temperature of 90 ℃, reaction time of 1 h and O 2 pressure of 0.4 MPa, the oxidized lignin had the highest content of acid soluble lignin.