316L austenitic stainless steel samples were prepared by warm compacting and vacuum sintering powder metallurgy method. Effects of sintering temperature on microstructure, phase and mechanical performances such as hardness and tensile strength was investigated. And corrosion weight loss curve, anodic polarization curve, Nyquist diagram and Mott-Schottky curve were studied to investigate the immersion corrosion behaviors of the sintered 316L austenitic stainless steel in 3.5 wt. % NaCl solution. Tensile fracture，immersion corrosion morphology and passivation film composition and elemental valence was analyzed by SEM (Quanta 450 FEG), laser scanning confocal microscopy (LSM 800) and XPS (AXIS Supra) respectively. Results shown that the highest sintering density (7.203 g?cm-3),elongation(65.46%), mechanical tensile strength (420.368 MPa) and hardness (63.1 HRB) are achieved after the samples were warm compacting at 115 ℃ and vacuum sintering at 1290 ℃, and presented high toughness with the tensile fracture morphologies of ductile rupture, deep and numerous dimples. In addition, the lowest corrosion current density (5.07×10-5 A?cm-2), the carrier density (7.23×1019 cm-3), the highest charge transfer resistance (8111 Ω?cm-2) and passivation film resistance (14780 Ω?cm-2) among the sintered samples after 600 h immersion in 3.5 wt. % NaCl exhibited very good corrosion resistance.