Abstract: The origin of various overlap interference of spectrum peaks in isotope mass spectrometry and the methods for eliminating the/nterference are described. Based on the ionization forms and the isotope components of common elements, their mass spectrometric peaks which may be overlaped are arransed in two tables according to the order of mass charse ratios. The results show that there are 50 and 77 mass charse ratios where the overlap interference of spectrum peaks may occur respectively in surface ionization and electron bombardment ionization mass spectrometry.