A circularly polarized wideband microstrip antenna with high gain and array is presented. In order to achieve wideband and high gain, a parasitic patch and the air layer are added to the antenna which works at 2.6 GHz center frequency. Two square patches with different sizes on two dielectric layers are corner-truncated with perturbation to excite circular polarization operation at a low and a high frequency, respectively, which effectively broadens the axial ratio bandwidth. The simulated bandwidth is 21.8% with the reflection coefficient |S11|<-10 dB, the 3dB axial ratio bandwidth is 12.0%, the gain is 9.0 dBi at center frequency. The prototype is fabricated, and the measurement results coincide with those of the simulation. A 2×4 antenna array is designed, the simulated gain goes up to 17.5 dBi and the 3 dB axial ratio bandwidth maintains 10.4%.