Monolithic microwave integrated circuit (MMIC) has played an important role in consumer and military applications.Among MMICs,high power amplifier is indispensable and the most complex component which enable transmitter delivers signal with sufficient power into free space.This paper provides chip designers a comprehensive design references and reviews the current development status of MMIC power amplifier basing on academic reports and commercial products datasheet.Firstly,various MMIC PA fabrication technologies classified as GaAs,GaN,CMOS and SiGe etc.are discussed.Then MMIC PA design techniques for satisfying specifications like high power output,broadband and high efficiency are introduced.Finally,paper concludes the processes and design techniques for MMIC power amplifier.