Abstract: This paper describes a new structure of solid state transmitter for a high mobility radar. The transmitter is designed to be assembled in a shelter. Its solid state power amplifier units and switching power supply units share a static pressure box, and cooling air is offered by a fan. Rectangular chaped power divider and combiner are firstly designed and used in the transmitter. The new structure of the transmitter ,assembly and connection,cooling design and its major sub-units are analyzed. The new structural design simplifies the transmitter structure,and is convenient to operate the transmitter. The starting time is shortened and the performance is improved. The trend of development of structure of solid state transmitter are discussed. It may be a valuable ref- erence for solid state transmitter study.