The detection of DNA contents and ds-DNA cross-link in HeLa line, HL-60 line,proliferative and non-proliferative T lymphocytes with EB-fluorescence assay was investigated, and study on the correlation of cell proliferative activity with its ds-DNA cross-link was carried out as well. The results show that the percentages of ds-DNA cross-link in HeLa, HL-60 line, proliferative and nonproliferative T lymphocytes were 36.5, 22.2,20.2 and 0 respectively, and that the proliferative activity of cells has a relationship with their ds-DNA cross-link，and nonproliferative or G₀ phase cells do not produce ds-DNA cross-link.