Abstract: A dyed polyester fiber composite structure having an enhanced brilliance and/or color depth, comprises (A) a dyed porous polyester fiber which has been produced (1) by preparing a polyester resin from a dicarboxylic acid component and a glycol component in the presence of a pore-forming agent containing 0.3 to 3 molar % of at least one phosphorus compound based on the molar amount of the dicarboxylic acid component, (2) by converting the polyester resin to a polyester fiber in which fine particles of the pore-forming agent are dispersed, by treating the polyester fiber with an aqueous alkali solution so that at least 2% of the weight of the fiber is removed and a number of fine pores are formed in the fiber and (4) by dyeing the porous polyester fiber; and (B) a coating layer on the peripheral surface of the dyed porous polyester fiber, comprising a polymeric material having a smaller refractive index than that of the porous polyester fiber.