This paper, using the frequency bandwidth, where both the gain and the VSWR (Voltage Standing Wave Ratio) of a monopole can satisfy the design requirement, as object function, mainly describes the process, in which the load locations, the matching network topology and their component values are optimized by the AGA (Adaptive Genetic Algorithm), to achieve a gain more than -2 dB in horizontal direction and a VSWR less than 3 in bandwidth as wide as possible. Moreover the design results are presented for monopoles with two concentrated loadings. It shows that the AGA is an effective method for designing wideband antennas. This paper, using the frequency bandwidth, where both both gain and the VSWR (Voltage Standing Wave Ratio) of a monopole can satisfy the design requirement, as object function, primarily describe the process, in which the load locations, the matching network topology and their component values ​​are optimized by the AGA (Adaptive Genetic Algorithm), to achieve a gain more than -2 dB in horizontal direction and a VSWR less than 3 in bandwidth as wide as possible. Moreover the design results are presented for monopoles with two concentrated It shows that the the AGA is an effective method for designing wideband antennas.