This work was focused on the investigation and growth of resistance spot welding of automotive grade Advanced High Strength Steel DP-780. Experimental work was carried out on different resistance spot welded specimens. The main purpose of this work was to find out the adequate range of spot weld parameters for AHSS galvanized DP-780 steel. Selection of welding parameters should be suchthat nugget pulloutfrom the sheetcan be assuredto ascertainthe reliability of resistance spot welds. In this workone factor at a time (OFAT) approachwas followed to investigatethe influenceofwelding parameters viz. weld current, weld time, and electrode pressureon the nugget developmentand strength of the weldments. Effects of some other interdisciplinary data like, heat input, mean DCR, failure energy etc. were investigated as well. Increase inwelding current value abovea certain critical value led to the transition from interfacial failure mode to pullout failure mode resulting improved energy absorption capacity of the joint.Two stacksresistance spot welding is mostly used in automotive body structureapplications. Nevertheless, in automobile or other many applications,resistancespot welds between multiple stacksheets are requireddue to some limitations in structural designof the components. So here a small experimental analysis on three stack resistance spot welding in addition to two stack resistance spot welding was also carried out. of the resistance spot welds were investigated using for three stack resistance spot welding. Similarto two stack resistance spot weldingone factor at a time approachwas used to analyze and investigatetheinfluenceof variouswelding variablesviz. weldingcurrent, weldingtime, and electrode force on the nugget growth, nugget size and tensile shear strength