The circular polarization microstrip antenna is one kind of low cut plane antenna element . Researching circular polarization microstrip antenna property is very important in antenna design. And how to find the feed place is the key to design. Researching makes a detailedly analysing and expounding of the pentagon circular polarization microstrip antenna in view of the single ended side. The microstrip antenna realization means is introduced. The way to analyze polygon microstrip antennal is given, which is named finite cell. By adjusting the 5.6 GHz pentagon circular polarization microstrip antenna, we give out the circular polarization microstrip antenna design processing. The feed place is found with the right means. Adopting HFSS software to optimize the design , and carries on imitation , give out the right imitation result .