Abstract: According to the problem of union dyeing of wool/silk blends with one bath and one step dyeing,the low temperature dyeing with redox system was used in the one bath and one step dyeing of wool/silk blends.The results showed,under the redox system of H2O2/NH2CSNH2with the ratio of 0.045 mol/L∶ 0.015 mol/L,wool and silk fabrics were dyed in low temperature dyeing at 80℃with selected weak acid dyes respectively,the dyeing uptakes and the color yieldsK/Svalue of wool and silk fabrics were equal to or exceeded those dyed with normal boiling dyeing condition.The H2O2/NH2CSNH2redox system could improve the union dyeing property of wool/silk blends in the one bath and one step dyeing obviously.The UV and visible spectrum analysis revealed that the color of the dyeing solution was not changed under the redox system,and the washing fastness and rubbing fastness were not influenced either.