The work summarizes the review of use of High Entropy Alloy in the Friction Stir Welding. When High Entropy Alloy is utilized in the Friction Stir Welding the resultant mechanical, metallurgical as well as corrosive properties show the influence of HEA base material properties. The Process used to obtain HEA provides base properties affecting the microstructural impact due to heat generation in FSW. Taking into account HEA, FSW too improve the welding properties of the material. The grain size was affected by heat generation and pressure of rotational as well as transverse speed, and could be differentiated in different zones (SZ, HAZ, and TMAZ) and sides (advancing, retreating, top, and bottom). Results of misorentation, HABs, and LABs were influences by the type of recrystallization. GGAE are associated to HABs and SFE to heating phenomenon, so overall it is HEA reaction to the heat generation in different areas and its effects seen in recrystallization of grains.