Abstract: Two kinds of horizontally polarized omni-directional conformal microstrip antenna are presented in this paper .The return loss and horizontally directivity of this conformal microstrip array antenna are simulated using CST MWS. First, theconformal microstrip antenna is designed by symmetrical structure, and using the single radial property of the microstrip patchantenna, the omni-radiation in horizontal direction is realized. Then, th return loss and radiation pattern are analyzed. At last,the influence of the characteristic of the omni-directional radiation is studied. The research in this paper is significant to designand application of horizontally polarized omni-directional antennas.