The design method of a new microstrip patch antenna with adjustable frequency is presented in this paper. Although the design technologyof microstrip patch antenna has been relatively matured in many years ago, sometimes there is always some unpredictable deviation during the design and application, which needs designers to further study the characteristics. A right-handed circularly polarized antenna with frequency from 2.38 to 2.50 GHz has been designed by using the conventional design method, but the measuredfrequency is from 2.41 to 2.55 GHz. The frequency is shifted to the high frequency and cannot be used. The aforementioned question can be solved by using the new structure microstrip patch antenna with adjustable frequency.