Abstract: THE APPLICATION OF RADIOTRACER TECHNIQUE FOR PRECONCENITRATION NEUTRON ACTIVATION ANALYSIS Wang Xiaolin Chen Yinliang Sun Ying Fu Yibei（Southwest Insitute of Nuclear Physics and Chemistry, Chengdu 610003）ABSTRACT The application of radiotracer technique for preconcentration neutron activation analysis（Pre-NAA）are studied and the method for determination of chemical yield of Pre-NAA is developed. Thismethod has been applied to the determination of gold，iridium and rhenium in steel and rock samplesand the contents of noble metal are in the range of 1-20 ng·g~(-1)（sample）．In addition,the accuracydifference caused by determination of chemical yield between RNAA and Pre-NAA are also discussed.Key words radiotracer preconcentration neutron activation analysis noble metal