In this research, investigation of mechanical properties and microstructure on Pulsatile Current Gas Tungsten Arc Welding (PC-GTAW) was carried out. AISI 304L was chosen as a base material with autogenous welding and butt joint configuration. The dimension of the base material was 120 x 50 mm and the thickness of 3 mm. The welding with pulsatile current and constant current were used in the welding process in this study. In the pulsatile current, the mean current was made all the same with a constant current of 100 amperes. The peak current, base current and time of peak and base current were varied to make it the same. The welding speed used is constant at 2.0 mm/s. The result shows that the HAZ area will get shrinkage if welded using pulsatile current welding. The welding with a pulsatile current can produce more fine cellular dendritic structure than the welding with a constant current. The UTS in the welding with a pulsatile current was lower than the welding with constant current, while the impact toughness in the welding with a pulsatile current was higher than the welding with a constant current. The highest of the UTS and the impact toughness of 577.62 MPa on parameter 65-A and 27 J on parameter 65-C, respectively.