A circular polarized antenna structure is provided, including: an antenna having a main body, a protruding portion, and a stopping portion formed between the main body and the protruding portion; a base; a radiation conductor disposed on an upper surface of the base and having at least a first through hole formed above the via hole; a ground conductor disposed on a lower surface of the base and has at least a second through hole formed below the via hole; solder partially covering an end of the stopping portion opposing the main body and the first through hole; and colloid partially formed on the solder, the radiation conductor, and the upper surface of the base. The antenna penetrates the base, and the stopping portion abuts against the lower surface of the base, such that the antenna can be prevented from dropping due to the impact of an external force.