Abstract: To distinct the mechanism of an antimutagen with SOS inductest ,the authors designed a series of lab procedures which could reveal whether the antimutagen deactivate a given mutagen ext racellularly or protect the targer cell against mutagenesis ext racellularly ,whether the antimutagen interrupt mutagensis int racellularly or has an ability to repair damage caused by the mutagen. After using Vitamin C as a standard antimutagen ,we found that the lab procedures could be put into practice effectively.

Key words: Antimutagenicity, Mechanism, Lab designing