Nine “single energy” gamma standard solutions are used to calibrate the peak and total efficiencies. True coincidence summing（TCS） corrections in γ spectrum analysis of 60Co、152Eu and 154Eu in cylindrical volume soil samples measured on the top of a HPGe detector with 100% relative efficiency have been studied. The experimental TCS correction factors have been measured by comparing the calibrated efficiency function after correction for self absorption and the efficiencies measured by using standard soil sources

which are 1.10 and 1.14

respectively

for 60Co 1173 and 1332 keV γ-rays. TCS correction factors have also been calculated by using efficiency functions and decay schemes

which are 1.10 and 1.11

respectively

for 60Co 1173 and 1332 keV γ-rays. A relatively strong sample has been chosen to be measured on and far away from the detector surface

and the 137Cs 661 keV peak has been used as a transition to get the TCS correction factors

which agree satisfactorily with those derived by other methods.