Abstract: By means of Ames test , the genetic toxicology of chlorination on drinking eater is evaluated. The result showed that the mutagenecity of water increased in all samples t reated with chlorine , while mutagenic potential was negative in source water samples not t reated with chorine. By adding Na2S2O3 to chlorinated water samples , there had less mutagenic activity. The antimutagenic potentials of Na2S2O3 in the chlorine water was dose dependent , the higher the mutagenicity of chlorined water , the better the beneficial effect of nasal. These indicated that the mutagenecity in chlorined water can be reduced by water t reatment process.

Key words: mutagenicity, Ames test, chlorine, drinking water