Abstract: A dual-band and high-gain microstrip antenna based on double screen FSS(Frequency Selective Surfaces) partially reflective surfaces is designed and fabricated. The FSS structure is constructed by printing two annular square patches on both sides of the surface respectively. Changing the dimenson of each annular strip patch to achieve dual-band resonances with FR(Frequency Ratio) to 2, positive reflection phase gradients(the general is with negative reflection phase gradients) and the reflection magnitude above 0. 86 and 0. 82 respectively in 5. 12 ~5. 31GHz and 10. 08 ~10. 84GHz. The radiation caliber of microstrip is increased by using FSS as the radome of dual-band microstrip antenna so that the radiation performance is effectively improved. The simulated and measured results show that: comparing to primary antenna, the gain of the antenna with FSS radome is increased by 4. 8 dB and 5. 1 dB at 5. 22 GHz and 10. 43 GHz respectively.