Abstract: Objective To study the antim utagenicity of water extracts from Momordica charantia.Methods The cometa ssay and Ames test were used to de tect the antimutagenicity of water extracts from Momordica charantia.Results The comet assay results showed that there was significant difference between the negative control and the treated groups in dose of 2.5,5.0,10.0g/kg·bw(P<0.05).The water extracts from Momordica charantia could reduce the damage of cell caused by cyclopho sphamide.The Amestest results showed that the increasing of the frqeuency of revertant colonies of TA98,TA100 treated with positive mutagens could be inhibited by the 5000,1667,556μg/plate of water extracts from Momordica charantia with or without S9.Conclusion The water extracts from Momordica charantia can inhibit mutagenesis.