Abstract: The metallurgical,physical and mechanical performance,and the corrosion and welding properties 0f 00Cr17Ni12Mo2（controlled Nitrogen,ANSI316LN） and 0Cr18Ni10Ti（ANSI321SS） for main pipe material were analyzed comparatively in this paper.The feasibility of 316LN pipe material manufacturing was studied too.The analysis results showed that under the operation condition of the nuclear reactor,the general properties of 316LN are better than that of 321SS.Therefore,316LN could be used for main pipe material,replacing 321SS.