Abstract: THE DETERMINATION OF SE CONTENT IN SE EGG BY NAA IN MNSR Wang Ke Hou Xiaolin（China Instituet of Atonic Energy，Beijing 102413）ABSTRACT The selenium contents in the yolk ，albumin and shell of the egg which was laid by layer hen fedwith various se concentrations are determined by thermaI neutron activation analysis with a nuclear re-action ~(78)Se（n. γ）~(77)Se on the miniature neutron source reacter（MNSR）．The resuIts show that themore the selenium added to the feed，the higher the se content in the egg and that in the egg con-stituents，the highest Se content is in the egg yolk and the lowest in the egg albumin. Key words selenium egg neutron activation analvsis miniature neutron source reacter