Abstract: High electron mobility transistors(HEMTs) made by GaN, due to its high power density and high speed features,become hot topics both at home and abroad.At the same time, the class E power amplifier, having a characteristics of high-efficiency and wide band,shows a broad prospect of application.In this article ,we choose a GaN HEMT devices made by Nanjing Electronic Devises Institudeto do some research of GaN class-E power amplifier.On account of the high output capacitance of GaN HEMT, we use the compensation microstrip structure to reduce the influence of parasitic parameters,and then designed a GaN class E power amplifier working at 13.7 GHz ~ 14.2 GHz. The measured data shows that drain efficiency is more than 36%, the output power greater than 30 dBm when the continuous wave power is 25dBm.