Abstract: Biological effects and applied research of heavy ion beams in life sciences have been extensively developed in the field of physics and life sciences at home and abroad. To some appearances, however, their essence have not been profoundly exposed and expounded in mechanisms. In order to deeply study them, several valuable matters are for reference only put forward such as model for track structure and energy deposition distribution of heavy ions, sensitive sites of DNA to radiation, mass deposition-molecule reform, direct and indirect actions, application of radioactive ion beams and so on.