Abstract: Objective To compare the damage effects of crown in on mitochondrialDNA (mtDNA)and nuclea DNA (nDNA)in human colon cancer cell line HT-29.Methods After HT-29 cells were exposed to various concentrations of cureum in (0,2.5,5.0,10.0,20.0μg/ml) for 2h,high molecular weight DNA was isolated and long polymerase chain reaction (LPCR) assay was perfouned to deteun ine the damage of mtDNA and nDNA.Results A 2h exposure of HT-29 cells to cureum in led to a dose-dependent decrease in the amplification of both mtDNA and nDNA.Loss of amplification of the mtDNA occurred at a lower dose of curcum in (5μg/ml) compared with the nDNA(10μg/ml).For mtDNA,DNA lesion frequencies for groups with different concentrations of cureum in (5,10 and 201μ/ml) were 1.23±0.10,1.97±0.24 and 5.78±0.62 lesions/10kb(P<0.01),and that of for nDNA were 0.27±0.04,0.61±0.11 and 1.61±0.12 lesions/10kb,respectively.Conclusion In HT-29 cells,curcum in induces DNA dam age to both m1DNA and nDNA,and the damage to mtDNA is more serious as compared with nDNA.