Abstract: A conical conformal circular polarized (CP) antenna array is presented for GPS L1 frequency (1.575GHz) and BeiDou B1 frequency (1.562GHz), which realized omni-radiation in horizontal direction. The influence, such as S11 11, axial ratio and CP gain of the antenna element swapped on cone are studied and compared by using HFSS. The circular polarization performance and the CP gain are improved by adjusting the dimension of the patch. The measured results show that , S11 is less than -10dB in the band of 1.556 ~ 1.578 GHz, the maximum CP gain of the in horizontal direction is 2.08dB in L1 frequency point and 1. 19dB in B1 frequency point, and the out of roundness of the radiation pattern is less than 2dB. It shows the antenna has good CP omni-radiation performance in horizontal direction.