A bisazo reactive dye represented by a free acid of the formula, ##STR1## wherein X.sub.1 and X.sub.2 are each a hydrogen atom, a methyl or methoxy group, a chlorine atom, or a carboxylic acid or sulfonic acid group, Y is a hydrogen atom, a methyl or sulfonic acid group, Z is --CH.sub.2 CH.sub.2 OSO.sub.3 H, --CH.sub.2 CH.sub.2 OPO.sub.3 H.sub.2, --CH.sub.2 CH.sub.2 Cl or --CH.dbd.CH.sub.2, and Z.sub.1, Z.sub.2 and Z.sub.3 are each a hydrogen or chlorine atom, a methyl, methoxy, sulfonic acid or carboxylic acid group. This dye is usable for dyeing cellulose fibers in a deep blue color with good fastnesses, particularly, chlorine, light and perspiration-light fastnesses, a high acid stability, good white dischargeability as well as level dyeing properties.