The wash-fastness of dyed polyester filament fabric was investigated using disperse dyes having different chromophores such as azo, anthraquinone, and benzodifuranone. The most important factors agnting the wash-fastness were fond to be the hydrophilicity and size of Planar region of disperse dye. The dye Possessed high hydrophilicity, which could be calculated by inorganic-organic-balance, showed Poor wash-fastness. The disperse dye having large planar region in molecular structure, for example the dye derived from benzodifuranone, showed extraordinarily high wash-fastness. The condition of washing test was also an important factor because it might change the degree of wash-fastness according to its severity.