Abstract: Solid solution and aging treatment of hot rolled Ni-saving high nitrogen austenitic stainless steel were carried out. The effects of solid solution and aging treatment on the mechanical properties of the test steel were systematically analyzed by means of microhardness testing, room temperature tension and TEM. The results show that, with the increase of the aging temperature, the tensile strength and yield strength of the test steel show first increase and then decrease. When the aging temperature is 750 ℃, the strength is the highest. The extension and shrinkage of the test steel increase with the increase of aging temperature. When aging at 750 ℃ for 5 h, the test steel shows the best comprehensive properties. Combined with transmission electron microscope analysis, there are three stages in the tensile deformation process of the test steel. In stage Ⅰ,the true stress increases rapidly, and the dislocation strengthening mechanism is the main mechanism in this stage. In the second stage, matrix softening and processing hardening still play a leading role. In stage Ⅲ, the work hardening rate generates a small platform with the increase of true strain（ε=0.24）, and then decreases gradually until fracture.