The use of electric voltage will be associated with heat input. Sufficient heat input is needed to form a good nugget structure so that it can produce maximum joint strength. By setting the parameters of the amount of voltage given, good connection quality will be produced. The purpose of this study was to determine the effect of variations in electrical voltage and time on tensile strength and microstructure of spot welding of dissimilar stainless steel 430 and galvanized steel. The voltage variations used are 1.60 V, 1.79 V and 2.02 V. The welding time used is 2-6 seconds. The test specimens used stainless steel material 430 with galvanized steel with a thickness of 0.8 mm each. The research carried out is a tensile test according to ASME (American Society of Mechanical Engineering) standards and microstructure testing. The results of the study show that the best tensile test results occur at a 2.02 V electric voltage which gives a tensile strength of 2728.575 N. Observation of the microstructure between stainless steel 430 and galvanized steel is dominated by perrit and kabrida structures, where almost all of the structures 430 stainless steel is dominated by ferrite because stainless steel 430 is stainless steel. ferritic with a content of C ≤ 0.12%, so that with very low levels of C it makes the carbide formed a little. It can be seen that the microstructure of the galvanized steel metal structure seen by pearlite and ferrite, where the two phases are spread evenly. There is more perritic structure than ferlite in the parent metal, this is because the HAZ region of galvanized steel undergoes a welding cycle which causes the area of the HAZ to become larger and changes the microstructure of the material into coarse grains.