Abstract: Reactive azo dyestuffs which, in the form of free acid, are represented by the following formula: ##STR1## (wherein R is hydrogen or methyl) are characterized by exhibiting the following properties: high fixation efficiency, excellent wash-off, high build-up and excellent wet fastness. Such dyestuffs give dyeings excellent in light fastness, chlorine fastness and color yield.

Abstract: A reactive disazo compound which, in the free acid form, is represented by the formula: ##STR1## wherein R.sub.1 is H, Cl or SO.sub.3 H, R.sub.2 is H, CH.sub.3 or SO.sub.3 H, X is .beta.-sulfatoethyl, .beta.-thiosulfatoethyl, .beta.-phosphatoethyl or vinyl, Y is Cl or F, Z is Cl, F or Z.sub.1, Z.sub.1 is amino; mono- or dialkylamino having 1 to 4 carbon atoms which may be substituted by hydroxy, carboxy or sulfo; morpholino; anilino which may be substituted by halogen, lower alkyl, lower alkoxy, carboxy or sulfo; N-methylanilino, naphthylamino or sulfo-substituted naphthylamino; alkoxy having 1 to 4 carbon atoms which may be substituted by lower alkoxy; phenoxy; alkylthio having 1 to 4 carbon atoms which may be substituted by hydroxy; phenylthio, and Q is N, C--Cl or C--F when Z is Cl or F and N when Z is Z.sub.1. These compounds are used for dyeing or printing cellulosic fibers.