Abstract: Effect of zinc nutrition on endogenous hormone and free radicals in spring maize (Zea Mays L.) were studied by field trial,plant analysis and physiological determination. The results indicated that zinc deficiency was found in ear leaf during grain formation in the treatment without zinc added in zinc deficient soil, while that was not found in the treatment with 30kg/hm2 zinc was added. It seemed that IAA and GA3 synthesis could be retarded in ear leaf in zinc deficient soil. Zinc application could increase SOD activity and reduce MDA content in ear leaf, which was beneficial to lower the free radicals injury to plants.