The present invention relates to a reactive orange dye containing vinyl sulfone and more particularly, to the dye which have 6(7)-alkoxycarbonylamino-4-hydroxy-2-naphthalenesulfonic acid as a chromophore and aminophenyl--ethylsulfone derivative as an azo coupler. This dye provides excellent fastness in terms of light, washing, perspiration and chlorine as well as better dyeing yield than other monofunctional reactive dye. In Formula (1), M is alkaline metal atom; Z is —O—SO₃M or OC(O)CH₃; R is alkyl group having 1-4 of carbon atom; and a position of C₆ or C₇ is substituted with carbamate group.