A receiving device for a global positioning system and an antenna structure thereof. The receiving device includes a housing, a circuit board and the antenna structure. The circuit board is disposed inside the housing and has a ground portion and a signal feeding portion. The antenna structure is disposed inside the housing and includes a metal plate, a first electric conducting element and a second electric conducting element. The metal plate is used for receiving a GPS signal. The first electric conducting element has one end coupled to the metal plate, and the other end coupled to the ground portion of the circuit board. The second electric conducting element for feeding the GPS signal to the circuit board has one end coupled to the metal plate, and the other end coupled to the signal feeding portion of the circuit board.