The paper reported the induction of micronuclei (MN) and structural chromosomal aberration (SCA) in human embryonic lung fibroblast cell (KMB) by water supply. The correlation of SCA and MN, NDI and MI was also reported. The organic extracts of both source and drinking water could induce the SCA and MN formation at different doses. NDI and MI decreased with the increase of sample doses (r = -0.904 and -0.980 in source water and r = -0.882 and -0.918 in drinking water, respectively). These data suggested a good correlation between chromosome damage as measured by MNBN and aberrant cells and cytotoxicity as measured by NDI and MI. Correlation coefficients of source and drinking water were 0.886, 0.958, 0.994 and 0.960 respectively.