In this paper, the design for a PCS base station antenna which is using broadband method by a stacked structure has been studied. The sensitive parameters, such as the parasitic elements, the height of air layer between the upper and lower patch, and the variation of feed point, of the microstrip antenna that has stacked structure in a characteristics variation situation are classified and the characteristics has been investigated through the simulations. A designed antenna has following characters. Impedance bandwidth is Z57.5MHz(VSWR${leq}$2), horizontal beamwidth is $64.1^{circ}$, and gain is 14.7dBi. Therefore, it is confirmed the characteristics is good. In this paper, through the designing of a stacked microstrip antenna, we has investigated the availability for Korea PCS base station antenna.