To provide a dyeing process improved in level dyeing, light fastness, buidup, and a pH dependency by dyeing a fibrous material with an anthraquinone disperse dye.

Provided is an anthraquinone disperse dye of the formula (wherein n is 0.3-0.6). In dyeing with this dye, the anthraquinone disperse dye of the formula is dispersed in an aqueous medium with the aid of a dispersion medium to prepare a dye bath or a printing paste, and a fibrous material is dipped or printed. The fibrous material to be dyed is exemplified by a polyester fiber comprising a polyethylene terephthalate or a polycondensate of terephthalic acid with 1,4-bis(hydroxymethyl)cyclohexane, a natural fiber such as cotton, silk, or wool, or a mixed-spun or-woven fabric of a synthetic fiber such as a nylon with a polyester fiber. The pH of the dye bath is in an acidic or alkali region.