Aluminum AA2024-T4 and Titanium G2 sheets were joined by resistance spot welding successfully. Welding parameters used are; current 60 amps, holding time 3 seconds, and with three different pulsations. One pulse, three pulses, and five pulses with pulsation time being one second. Mechanical (tensile, microhardness, and microstructure) and chemical (corrosion) tests were carried out and compared for each welded plates with different pulsations (1, 3, and 5 pulses) for the same conditions Aluminum-Aluminum, Titanium-Titanium, and Aluminum-Titanium for a complete and comprehensive comparison. Through the results obtained, the optimum results were obtained for spot welded Al-Ti (Al-Ti 603) with (3) pulses, where a maximum tensile strength value of 135MPa, a corrosion rate of 0.00308mm/y, and a microhardness between (215-198 HV). A spot welded joint was obtained with partial fusion, clear overlapping vertical granular areas, and no cracks compared to other joints, which show cracked areas, lower strength and microhardness values, and a higher corrosion rate.