In recent years, the advent of Metal Oxide Semiconductor Field Effect Transistor (MOSFETs) rank as one of the most significant development in power electronics. Its ability to work at high-voltage and high-frequency make MOSFETs become the most important electronic device for many power system circuit. For harsh environment application in example the satellite system, requires the MOSFETs dealing with the radiation exposure which then causes ionizing radiation phenomena in the devices. Basically, the radiation's source in the harsh environment divided into two types which are; photon radiation and particle radiation. The radiation exposure may affect MOSFET's performance by changing the electrical characteristic and properties because of its occasion of a shift in threshold voltage (Vth) and changes in drain-source resistance (Rds). Moreover, there are two major catastrophic outcomes on MOSFETs which are; Single Event Gate Rupture (SEGR) which affects the functionality of the gate dielectric and Single Event Burnout (SEB) which results in shortening the drain to source current (Ids). Eventually, the primary focus of this paper is to study the topology of instantaneous radiation effect on MOSFETs for harsh environment application. All the information and data that will be discuss through this paper is getting from the literature surveys activities. © 2017 IEEE.