A display substrate includes a plurality of pixel parts, each including a first and second gate lines, a source line, first, second, and third transistors, and a pumping capacitor. A display device includes a display panel, a gate driving part, a source driving part, and an output selecting part. Each pixel part of a display panel includes a transmissive part, a reflective part, and an adjusting part. The adjusting part adjusts the transmission voltage charged in the reflective part to a reflection voltage based on a control voltage. Thus, transmission voltage applied to the transmissive part is adjusted to reflection voltage to be applied to the reflective part. Therefore, optical reflectivity and optical transmissivity versus voltage are matched with each other, while embodying a single cell-gap and applying a single voltage.