The Zinc deficiency is a worldwide nutritional constraint for crop production in many types of soil, particularly in cereals growing in calcareous soil. Two field trials were conducted to study the effects of zinc fertilizer doses and application method on photosynthetic characteristics and grain yield of summer maize, from June to September of 2013, in Xun County (34°40′12″N, 114°32′24″E) and Yuzhou County (33°59′19″N, 113°33′47″E). Optimal Zn fertilizer application (30 kg ZnSO 4 •7H 2 O hm-2) increased chlorophyll content in leaves, improved photosynthesis, and increased grain yield of summer maize. At 15 kg ZnSO 4 •7H 2 O hm-2 , grain yield was higher in Xun County and lower in Yuzhou County when the entire amount was applied as basal fertilization as opposed to being split between the basal and foliar fertilization. The opposite result (grain yield lower in Xun County than in Yuzhou County) was obtained at 30 kg ZnSO 4 •7H 2 O hm-2. These results have important implications for guiding the rational application of Zn fertilizer and improving the grain yield of summer maize in Henan province.