Abstract: A series of compounds was synthesized, these compounds were tested for Hela-S₃cells in vitro for radiosensitizing activity. Five of them are 2,2′- (arylimino)-diethyl-sodium thio-sulfate and two of them are phenylalanine derivatives. Most of them showed various degrees of ra-diosensitizing activity. Among them, SER of L07 was 1.89 at 3 mmol, and had low cytotoxicity toHela-S₃ cells;ID₅₀ was 18.8 mmol. The relationship between radiosensitizing effects and chemicalstructure was discussed. It offers a base for further exploration of selectively hypoxic cell radiosens-itizers.