To find out the nutrient contents of temperate grasses on the south and north slope, a field experiment was conducted with five forage species of Dactylis glomerata, Festuca arundinacea, Phleum pratense, Agrostis gigantea and Trifolium repens. It was treated by randomized block design with 4 replications and lasted from September, 1983 to October, 1986 in Suweon. The results obtained are summarized as follows: 1. Mean chemical compositions except NFE and crude fiber of the forage species on the south slope were a little more contented than that of north. But all crude components were significant difference among the species on the south and north exposure. 2. Production of TDN (total digestible nutrient), StE (starch equivalent) ME (metabolizable energy) and NEL (net energy lactation) of different grass species on the north slope were much more increased by 5-30% per ha (Dactylis glomerata by 5-876, Festuca arundinacea by 5%, Phleum pratense by 24-26% and Agrostis gigantea by 25-30%) than that of same grasses on the south, however, those of Trifolium repens were much more increased by 4 1-42% per ha in the south. 3. Mineral contents, Ca/P ratio and K/ (Ca + Mg) equivalent ratio of the species were slightly different between the exposures. But considering the factors of occuring grass tetany, those of the forage species on the north slope were better than that of same species on the south.