PET fabric was dyed in black shade with disperse dyes of three primary color. The effect of combination ratio of dye concentration and energy type of disperse dye on dyeing and color property of black dyed PET fabric was investigated. Dyeing compatibility of disperse dyes of three primary color on PET was evaluated by comparison of dyeing rates of them. From the results, color property was dependent upon the combination ratio of dye concentration. In order to obtain low lightness ($L^*$) and black color, blue dye should be added enough. S-type disperse dye and $130^{circ}C$ dyeing was suitable rather than SE-type dyes or $120^{circ}C$ dyeing. Disperse dyes of three primary color used showed good dyeing compatibility at high dye concentration. Washfastness was fair to moderate and lightfastness was moderate.