Joining dissimilar metal often plays animperativerole in manufacturing, constructing advanced equipments and machineries. Dissimilar metals are to compose different properties of metals in order to minimize material costs and at the same time maximize the performance of the equipment and machinery. Fusion welding is one of the most widely used methods for the joining of dissimilar metals. Unfortunately Dissimilar Metal Weld (DMW) has several fabrication and metallurgical drawbacks that can often lead to in-service failures. Reliability of dissimilar weld joint in critical applications is largely considered by its relevant properties, which primarily depends upon microstructure of the weld metal and heat-affected zone (HAZ). This paper focus on effect of grain size, microstructure and the width of the heat affected zone by gas metal arc welding (GMAW) and pulsed current gas metal arc welding (PGMAW) of dissimilar γ-ss and HSLA steel. In comparison to GMAW, PGMA welds can have more amount of refined dendritic microstructure, decrease in grain size at heat affected zone and lower HAZ Width in both HSLA steel and γ-SSespecially with the lowering of summarized influence of pulse parameters factor (φ) at similar heat input per unit length of weld (Ω) has been observed. © TJPRC Pvt. Ltd.