Abstract: The study on effect of fertilizer application on nutritive quality and growth of hybrid sorghum grass shows that application of mixed NPK fertilizer not only improves hybrid sorghum grass biomass but also increases its output per unit area in terms of crude protein, crude fiber and crude fat. Among the factors influencing biomass production, the N produces the best effect followed by P and K. Plant height and variability of crude protein, crude fiber and crude fat contents mainly depend on variety characteristics. Fertilizer application impacts output per unit area of crude protein, crude fiber and crude fat mainly through biomass variation in hybrid sorghum grass. With regard biomass amount and quality of hybrid sorghum grass, optimum harvesting time is from post floral stage to intermediate maturity stage. If hybrid sorghum grass is harvested early or late, its biologic yield drops. The quality is much inferior at late harvesting.