An antenna structure includes a housing, four feed sources, a first radiator, a second radiator, and a third radiator. The housing includes a first radiating portion and a second radiating portion. The first to third radiators are positioned in the housing. The first radiator is spaced apart from the second radiator. The four feed sources respectively connect to the first radiating portion, the second radiating portion, the first radiator, and the third radiator. The first radiating portion activates a first operation mode and a second operation mode. The second radiating portion activates a third operation mode. The first to third radiators activate a fourth operation mode, a fifth operation mode, and a sixth operation mode.