The effects of Cr⁶⁺ on the DNA contents and DNA methylation in roots of wheat seedlings were studied.The results indicated that:（1） DNA contents in roots of seedlings were all markedly reduced by Cr⁶⁺,and the declining extent of DNA content in roots of 3-day-old seedlings was bigger than that of 10-day-old seedlings.（2） The 5-MeC content in the roots DNA of 3-day-old seedlings with 5-100 mg·L^-1Cr⁶⁺ treatment were higher than that of control seedlings.But in the roots DNA of 3-day-old seedlings,exception that the 5-MeC content with 100 mg·L^-1Cr⁶⁺ treatment was lower than that of control seedlings,5-MeC contents with the 5-80 mg·L^-1Cr⁶⁺ tested concentrations were still higher than that of control seedlings.Cr⁶⁺ can affect DNA methylation level in wheat seedling roots,thereby affecting the normal growth and development of wheat.