With a purpose of finding out the effects of phosphatic fertilizer application at the grassland establishment and management on the dry matter yield and quality of grasses, a field experiment was arranged with four treatments as a randomized complcte block design and lasted from September, 19 89 to October, 1991 in hilly area near Suwon. The results obtained are summarized as follows: 1. As a early plant growth. winter hardiness. growth vigour and coverage of grasses of the plots with phosphatic fertilizer were better than those of the plots without $P_2O_5$. and the effect of application at the management was much better than that at the establishment of grassland. 2. The effect of phosphatic fertilizer on DM yield of legume was higher than of grass. Total DM yield with phosphatic fertilizer at the only establishment (5.688 kg/ha). at the only management (8.014 kg/ha) and at both the establishment and management of grassland (1 1,082 kg/ha) was much more increased by 38, 95 and 169% than that without phosphatic fertilizer (4.1 19 kg/ha), respectively. 3. The chemical component of crude protein and crude fat with phosphatic fertilizer was a little higher, on the other hand, content of NFE was lower than that without $P_2O_5$ fertilization, but the contents of crude fiber and crude ash did not tend to differentiate between treatments. 4. Production of encrgy(TDN, StE and NEL) with phosphatic fertilization at the establishment and the management of grassland was appeared to increase by 34 to 390h and 72 to 99% than that without $P_2O_5$, respectively. Production of curde protein with $P_2O_5$ tended to be similar to production of energy.