Abstract : Two field experiments were conducted from 2005 to 2007 to determine the rates of seeding and nitrogen application for high production of winter cereals (i.e., barley, ray, and oat) used for whole crop silage (WCS). This study was done on silt loam soil in southwestern Korea, which is the largest paddy field area in the country. In the first experiment, one rate of N application (200 kg N/ha) was used for all crops but with different seeding rates of 240, 280, and 210 kg/ha for barley, ray, and oat, respectively. The highest dry matter yield obtained was 9.3 Mg/ha for barley, 7.7 Mg/ha for ray, and 8.9 Mg/ha for oat. In the second experiment, the seeding rates were 170 kg/ha (barley and ray) and 150 kg/ha (oat); and N application rates were 180 kg N/ha (barley) and 240 kg N/ha (ray and oat). The highest dry matter yield in this experiment was 9.4 Mg/ha for barley, 7.3 Mg/ha for ray, and 9.4 Mg/ha for oat. Results from this study indicate that high production of WCS using winter cereals in paddy field can be obtained with seeding rates of 210–280 kg/ha, and N application rates of 180–240 kg/ha.