The aim of this work is to study the low level 210Pb activityas an indicator of 210Po by using the 210Pb 61 keV beta-energyline. The 61 keV beta-energy was selected by setting the threshold and windowof the double channel analyser in coincidence. This selection is convenientwith the high sensitive beta scintillator (BP4) using the standard nuclearspectroscopic method.