Abstract:The effects of different fertilization treatments on growth development, photosynthesis and yield of summer maize were studied in a long-term field experiment in the National AgroEcological Experiment Station in Fengqiu, China, and the correlations between net photosynthetic rate, leaf area index and yield were analyzed. The results showed that plant height, leaf area index and yield of the nitrogen, phosphorus, potassium nutrientdeficiency treatments were decreased significantly compared with NPK treatments. The yields of P deficiency, N deficiency and K deficiency treatments only accounted for 10.78%, 21.14% and 83.43% of that NPK treatment, respectively. The correlations between leaf area index and yield was more significant than that between photosynthetic rate and yield, indicating that the yield in different fertilizer treatments depended primarily on the level of leaf area index, followed by the photosynthetic rate. The low yields under longterm nonfertilization or nitrogen, phosphorus, potassium nutrientdeficiency condition were mainly resulted from synthesis effects of the decreased leaf area index and net photosynthetic rate.