A support structure for supporting a display panel includes a support and a clamp. The support is rotatably coupled to the display panel. The clamp includes two clamping arms rotatably coupled to the support, a bolt and an adjusting nut. A slot is defined in each clamping arm. The bolt is extended through each slot and engaged with the adjusting nut. Therefore a distance between two distal ends of two clamping arms can be adjusted by screwing and unscrewing the adjusting nut along the bolt. A display device using the support structure is also provided.