A suspension structure for an electric wheelchair comprises a frame, two cantilevers, two drive wheels, two rollers, four wheel-mounting assemblies, two front wheel assemblies, two draglines and two rear wheel assemblies. When surmounting a barrier, the front wheel assemblies will pivot upward and press down the drive wheels through the cantilevers, thus improving the road holding performance of the drive wheels. In other words, the drive wheels and the front wheels can move interactively to surmount the barrier.