A study designed to determine the effect of nitrogen top-dressing on plant characteristics, yield, and protein content of winter wheat was undertaken at Kansas State College in the spring of 1944. Nitrogen fertilizer was applied prior to March 15 to strips of winter wheat in the permanent fertility plots. Yield, protein content, and other data were collected from the top-dressed and the untreated areas. The results indicated that spring applications of nitrogenous fertilizers increased the yield and also increased the protein content. The increases in yield were especially prominent on the plots which were adequately supplied with phosphate. Analysis of several plant growth characteristics indicated that much of this increase could be accounted for by increased tillering and by increased number of kernels per head. Other plant characteristics, such as kernel weight, had little, if any, effect on the increased wheat yields.