A dual frequency antenna is provided, which includes a helical radiator electrically connected to a main body via a feed point of the main body, a first radiator for generating resonance is formed on the lower portion of said radiator, a second radiator for generating resonance is formed on the upper portion of said radiator, wherein the resonance frequency of the second radiator is higher than that of the first radiator, and the helical pitch of the second radiator is larger than that of the first radiator. The dual frequency antenna easily enables tuning in a whole UHF frequency band, and work performance of an upper semi-sphere of the dual frequency antenna is improved in a GPS frequency band.