To evaluate atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) ecotoxicology in soil, the effect of atrazine on the activity of antioxidative enzymes (superoxide dismutase [SOD], catalase [CAT], and guaiacol peroxidase [POD]) was investigated in Vicia faba roots. Tissues from each treatment were collected on the days 7, 14, 21, and 28. Compared with the controls, SOD activity in V. faba roots was stimulated by the 2.5 mg/kg treatment and inhibited by the 5 and 10 mg/kg treatments, and CAT and POD activities in the 10 mg/kg treatment were inhibited on the whole. The Olive tail moments of single-cell gel electrophoresis of root cells were enhanced after treatment with different doses of atrazine on days 7, 14, 21, and 28, and significant differences were found compared to the controls. In conclusion, atrazine induces oxidative stress and DNA damage on V. faba.