Abstract: Among the reactive dyes,Reactive Black 5(Reactive Black KN-B) is the most versatile dye with the largest production volume.But its main drawback is not black enough.About ten years ago,Reactive Orange 82 was formulated using the principle of complementary color,the blackening was improved.However,some problem still remained.Improving the blackening of Reactive Black 5 is one of the hot topics under research,and the orientation is to select an orange or red reactive dye which has high solubility,and is substantive,reactive and compatible to Reactive Black 5.