In order to dye polyester/cotton blend fabric by one-bath dyeing process with single disperse dye, a novel hetero-bifunctional bridge compound(DBDCBS) was synthesized and utilized. The DBDCBS was designed to contain two different reactive groups such as ${alpha},{eta}$-dibromopropionylamido and dichloro-s-triazinyl groups. The ${alpha},{eta}$-dibromopropionylamido group shows considerable reactivity towards amines or amino groups at acidic condition and high temperature. In contrast, the dichloro-s-triazinyl group has reactivity towards hydroxyl groups at alkaline condition and room temperature. In order to examine whether as a bridge the compound could combine dyes containing amino groups with cellulosic substrates, disperse dyes containing amino group were tried to dye the cotton fibers pretreated with the DBDCBS compound. By the results, polyester/cotton blends were dyed by one-bath dyeing process with single disperse dye,1,4-diaminoanthraquinone.