Abstract: DETERMINATION OF COBALT IN OCEAN MANGANESE-IRON NODULE WangMin;XiaoDuyuan;WuGuoliang （Institute of Technical physics， Heilong jiang Academy of Sciences， Harbin150086）IvanankoV.MetelevA. （Institute of Chemistry，Far-East Branch of Russian Acdemy of Sciences）ABSTRACT Themeasurement of cobalt in ocean manganese－iron nodule is discussed.First, adopt the integralmethod to define the range of cobalt accurate to decima. Then through progressive approximatim，mi-nus area of background and influence of other neighboring elements，the exact area of cobalt can begot，a group of national standard samples are measured, and using linear regression method getsS_（meth）=0．024％. Key words isotope source X-ray fluorescence manganese-iron nodule cobalt