A pot experiment was conducted to study the effects of different concentrations of biuret on physiologicalindexes of maize seedlings. The results showed that CAT activity in leaves increased firstly and then decreased withthe increasing of biuret concentration in soil, which reached its peak when biuret concentration was 60 mg/kg（insoil）. The MDA content in leaves increased with the increasing of biuret concentration in soil, but chlorophyll con-tent showed gradual reduction trend. In addition, root length, root surface area and root activity decreased with theincreasing of biuret concentration. When biuret concentration was 40 mg/kg（in soil）, significant decreases were ob-served in root length and root surface area compared with the control. When biuret concentration was 60 mg/kg（insoil）, root activity decreased significantly and its physiological function was also damaged, resulting in direct dam-age to the growth of entire plant.