An antenna assembly includes a base, a ground surface, a first radiating portion, a second radiating portion, a third radiating portion, and a feed portion. The ground surface is arranged on a surface of the base. The feed portion includes a plurality of feed points mounted on the radiating portions. The first radiating portion and one feed point transmit and receive wireless signals at a first frequency band and a second frequency band; the second radiating portion and the third radiating portion couple with the feed points to transmit and receive wireless signals at a third frequency band and a fourth frequency. The first radiating portion, the second radiating portion, and the third radiating portion form several slot antennas. A wireless communication device employing the antenna assembly is also described.