An upholstered structure including an upholstery material for a chair or a backrest of a chair is proposed, which may achieve: reduced proportion of the appearance of the rear frame of the backrest over the appearance of the whole chair; more sophisticated design; reduced weight; reduced number of parts; and improved assemble-ability. In the chair having the backrest upholstered with the upholstery material over the front surface of the rear frame, the rear frame comprises a front frame to which the peripheral edge part of the upholstery material is fixed and an upper reinforcement frame rod. The laterally facing upper reinforcement frame rod is connected at its both ends to both ends of the laterally facing upper frame rod at the top of the front frame with the center part of the upper reinforcement frame rod separated backward from the upper frame rod.