Environmental and economic demands make it necessary for farmers to adopt   management systems that improve Nitrogen Use Efficiency. The premium paid to producers has made farmers striving for maximum grain protein levels because protein is a very important quality component of grains and an important attribute in the market place. The protein content of wheat grains approximately ranges from 8 to 20%. The optimization of nitrogen (N) fertilization is the object of intense research efforts around the world. Soil tests are capable of estimating the intensity of N release at any point in time, but rarely the capacity factor over a longer period. Fluorescence sensing methods have been used to monitor crop physiology for years, and they may offer solutions for N status diagnosis over reflectance-based methods. Developed precision management of nitrogen through precision agriculture allows growers to use fertilizer input on more productive areas as well as saving nitrogen costs across the field. On the other hand, grain protein in cereal crops as well as yield is receiving increased attention because of premiums being paid to producers. Research has shown that grain protein levels are mainly affected by N availability. This paper presents a model which was develop to determine the optimum rate of nitrogen for yield and protein content through using different indices from nitrogen sensor in winter wheat. This model will allow for mid season variable rate application of N fertilizer. For this purpose, an experiment was established to determine the effect of nitrogen on yield and protein content using a randomized block design by applying five different rates of nitrogen (0, 80, 120, 160, 200 kgN/ha) and the two different varieties of wheat. A quadratic polynomial model was best describe the relationship between nitrogen, yield and protein content for optimum nitrogen rate.