Abstract: STUDY ON THE ASSAY OF βRADIONUCLIDES USING CERENKOV COUNTINGLIU DAMING；GUO JINGRU；ZHANG SHULAN；LIU DAMING；CUI ANZHI（China Institute of Atomic Energy，P.O. Box 275（26），Beijing 102413）ABSTRACT A method for the assay of βemitting nuclides in aqueous solution by Cerenkov counting isstudied using a home-made liquid scintillation equipment．Effects of sample volume，quenchingand energy of β particles on experimental results are studied．It is found that some coloured ions，especially Cr~(3+)，cause serious quenching of Cerenkov emission but NO_3 ion hardly does.Key words Cerenkov counting βradionuclide Quenching