This experiment was conducted to study the effect of burning on the chemical composition of some predominant native herbage plants in Cheju island, and the effect of fertilizer on the chemical composition and nutrients digestibility of the mixed native herbage plants in Daikwannyung. The results obtained are summarized as follows: Crude protein content during the initial stage of growth was markedly increased by burning old grass for both grasses and legumes families during the preceding month of budding. Burning could also increase crude ash content of grasses for all stages of growing. The content of crude protein and phosphorus of native herbage species was considerably increased by fertilizer application. Fertilizer application could also decrease the crude fiber content of native grass. Although the degree of effect of fertilizer application on nutrient digestibility was somewhat smaller than on chemical composition, fertilizer application could improve the digestibility of nutrients in early stage.