Abstract Concerning the primary radiation processes of DNA and radiation modifiers a fast radiation protection mechanism-charge transfer protection has been explored. Some binary molecular mixtures, such as thymine-cysteine, thymine-histidine, dTMP-hydroxycinnamic acid derivatives, DNA-caffeic acid etc. have been studied in detail. The common features of charge transfer protection and sensitization, and their criterions have been derived, i.e. the charge transfer protector is a substance with higher EA but lower IP than the target molecule, but the charge transfer sensitizer is a substance with both EA and IP higher than the target molecule. Furthermore, H-transfer repair mechanism has been pushed forward based on the detailed examination of dTMP-cysteine, DNA-cysteine, thymine-AET etc. Elaborate exploration of excitation transfer between thymine and cysteine or aromatic amino acids has also been demonstrated. In accord with the above “three transfer” mechanisms, the general principle of suppressing chemical carcinogen has been discussed in detail.