For every manufacturing industry, materials that are applicable for particular conditions and are of low economy are highly required. Hence various studies are carried out to determine the working conditions for several materials. The wide application of steel in industry demands a significance study on physical, chemical and mechanical properties of steel, Here, the characteristic changes in the mechanical and microstructure properties due to the effect of heat inputs of gas tungsten arc welded AISI 316 Stainless steel were examined. The major issue faced during the welding process of stainless steel is the increase in grain growth in the heat affected zone (HAZ). The welding process have been carried out using three heat input parameters on the AISI 316 Stainless steel from the operating window of the gas tungsten arc welding process (GTAW) and they are categorized as low heat (2.563 KJ/mm), medium heat (2.784 kJ/mm) and high heat (3.017 kJ/mm) . These welded joints of AISI 316 SS have been subjected to evaluation of tensile testing microstructure and mechanical properties so as to interrupt and infer the impact of thermal arc energy on the mechanical properties and microstructure of AISI 316 SS welded joints. From this study, it has been inferred that the heat input has notable effect on Ultimate Tensile Strength, Hardness and Microstructure on AISI 316 SS GTAW plates.