Abstract: To investigate the effects of sintering temperature and atmosphere on the density, microstructure, and mechanical properties of powder metallurgy 430L stainless steels, the bulk 430L stainless steel samples were fabricated by vacuum and N/H atmosphere sintering at 1150, 1270, and 1310 ℃. The results show that the porosity decreases continuously with the increase of sintering temperature, and the density and elongation of the samples sintered in both atmospheres increase gradually. However, the tensile strength rises first and then declines owing to the growth of ferrite grains and the coarsening of second-phase particles. Compared with the samples sintered in N/H atmosphere, the vacuum-sintered counterparts possess higher density and elongation but slightly lower tensile strength at the same temperature. The stainless steels vacuum-sintered at 1270 ℃ exhibits the optimal comprehensive performance, with the bulk density of 7.29 g·cm^‒3, tensile strength of 427 MPa, and elongation of 21.6%.