Abstract: The effects of different combinations of the single-bath composite auxiliary agent for scouring and bleaching,processing temperature and time on the pretreatment of cotton knitted fabric were studied.The results showed that the best process conditions are as follows: composite auxiliary agent 15.5 g/L,at a liquor to fabric ratio of 1∶20 for 60 min at 95～100 ℃.When compared with the conventional alkaline scouring and hydrogen peroxide bleaching process,this single-bath preparation composite auxiliary agent can render the fabric better whiteness and wettability.It also has other advantages such as simplicity,convenience in handling,operation and storage,lower pH value of the waste water,less environment pollution,and higher effective ingredients.