Abstract: This paper presented a base station antenna using the coupling phase-shifter and genetic algorithm(GA) antennashaped-beam technology which is applied in the GSM1800 frequency-band. The phase-shifter has large phase variety rangethrough a series feeding structure. The experiment results show that the phase-shifter has a good amplitude and a small insertionloss in the working frequency band. Thus, the design of the base station antenna based on the phase-shifter mentioned above hasa good upper-side-lobe suppression and an accurate precision of downtilt-angle.