A leg structure of an electric table includes a pair of support assemblies (10), multiple horizontal rods (20) and a pair of drive assemblies (30). The support assemblies (10) are arranged spacedly and parallelly to each other. Each support assembly (10) includes a connecting rod (11) and a pair of telescopic posts (12). Each telescopic post (12) is connected and fixed to the connecting rod (11). Each horizontal rod (20) is separately connected to each support assembly (10) and is parallel to each other. Each drive assembly (30) is separately received in each support assembly (10) for driving each telescopic post (12) to ascend or descend. Therefore, the leg structure of an electric table may be easily assembled and the whole structure is stable.