Abstract: An ultra-fine grain high nitrogen austenitic stainless steel was prepared by mechanical alloying (MA) and the spark plasma sintering (SPS) technology.The XRD-patterns show that nitride in the powder disappeared during the milling and the matrix of sintered sample is austenite.Nitrogen analysis shows nitrogen content in the sintered sample is 1.19%.TEM shows grain size of sample is distributed from 50 nm to 100 nm.Energy spectrum shows element of nitrogen is evenly distribued in matrix of sample.Capability-testing shows that the hardness and tensile strength of the sample are higher than those of ordinary 304 stainless steel.Corrosion resistance of sample is more excelled than that of ordinary 304 stainless steel.