Abstract: The objective of this paper is to develop a comparative analysis of rectangular and triangular cylindrical microstrip patch antenna. In this study we would like to take into account the problems of resonance and radiation of cylindrical rectangular and triangular microstrip patch antenna. Design procedure involves parameters related to cylindrical microstrip elements to realize the desired resonant frequency, input impedance, radiation patterns etc. Transmission line model is used to calculate the input impedance of the patch, while cavity model is used to calculate its radiation pattern. For a cylindrical-rectangular microstrip antenna, it is observed that the beam-width, resonant frequency, and resonant resistance decrease with cylinder radius. The bandwidth is not sensitive to curvature but it decreases as substrate permittivity increases. Triangular microstrip antennas are a good substitute for rectangular microstrip antennas, especially in microstrip array designs, due to their similar radiation properties and because the triangular patch is physically smaller than the rectangular patch