In order to estimate the content of structural carbohydrates in forages produced in Korea. the analyses were carried out for 8 grasses and 4 legume forages at pasture in Livestock Experiment Station. The results obtained were as follows. 1. NDF, ADF, lignin and cellulose of grass forages considerably increased when their life stages progressed; 46 to 72%, 24 to 44%, 3 to 8% and 18 to 34%, respectively. 2. NDF, ADF, lignin and cellulose of legume forages changed less than those of grasses forages; 29 to 55%, 20 to 35%, 4 to 11% and 18 to 34%, respectively.