The different absorbed doses of 100 MeV / u 12C6 ion beams was used to investigate the DNA damages and relative mechanism of Saccharomyces cerevisiae. After irradiation, the survival rates were estimated, and the DNA double strand breaks (DSBs) were tested by pulsed-field gel electrophoresis (PFGE). At the absorbed dose of 50Gy, the yeast cells semi-lethal dose, a strains named CZF 303 was cultured after comparing the alcohol dehydrogenase Ⅴ(adh4) gene sequence of CZF303 with the original strain. It was found that heavy ion beam could cause serious damage of yeast chromosomal DNA meanwhile large doses could cause yeast cell death. And amount of point mutations were found in adh4, which might be heritable mutations if the absorbed doses were suitable. As conclusion heavy ion irradiation can induce heritable mutations on S. cerevisiae gene. And it is an excellent and efficient method for breeding mutants.Cited