A door trim assembly includes a weather strip and a door trim. The door trim includes a holder plate portion arranged opposite the weather strip, an upper holder portion and a lower holder portion projecting from the holder plate portion toward the weather strip, and a support portion. The lower holder portion has a lower holder basal portion continuing from the holder plate portion, and has a gap distance from the upper holder portion. The lower holder portion and the upper holder portion hold a stopper portion of the weather strip therebetween. The support portion is provided near a portion of the holder plate portion where the lower holder basal portion of the lower holder portion continues, and is elastically deformable so that the lower holder portion is moved downwardly to increase the gap distance according to insertion of the stopper portion into a space formed by the gap distance.