Corrosion resistance of high strength P/M Austenite type stainlees steels obtained by the addition of boron or phosphorus was investigated. In this experiment, corrosion tests by JIS method were carried out by intergranular and general corrosion tests, and the corrosion resistance was compared with P/M stainless steels (3 types) and wrought stainless steel. As a result, on intergranular corrosion test using 65% boiling HN03 solution, a boron 0.2wt% added P/M stainless steel shows good corrosion resistance and the corrosion loss values are equivalent as compared to wrought stainless steel. Phosphorus 0.2wt% added P/M stainless steel shows poor corrosion resistance because of localized corrosion of phosphide that precipitated along grain boundaries. On the other hand, on general corrosion test using 5% boiling H₂SO₄ solution, the behavior of corrosion is closely related to the density of specimens.