In this paper, we simulated a radiation pattern directivity of microstrip patch antenna for 9[GHz] using the computer. It is analyzed and compared the directivity of field characteristics at two different aspects. One is that of 1-dimension and 2-dimension array, the other is that of a linear and planar array antenna. We tried the constants for the simulation of teflon substrate, dielectric constant ${varepsilon}r=2.50$, ground plane conductor thickness t=0.03556, substrate height h=0.72188, dielectric loss degree $tan{delta}$=0.00085, characteristics impedence of line $Zo=50({Omega})$. The major advantage of microstrip patch antenna is that the arrangement of antenna is associated with the directivity and effectiveness. We have been studied the difference of the radiation pattern of antenna with wave variety through computer simulation.