These experiments were conducted to get high production and quality of whole crop winter cereals, Oat, Wheat and Triticale, in the paddy field. These three whole crop winter cereals are got later harvest than whole crop barley, so there are more production of forage. Its harvest time was the end of May or the early of June in the south area of Korea. Mixed cultivations of Oat and Wheat (MCOW) was got more production over 15 percents in the dry wight, and then contents of crude protein (CP) in MCOW were higher than single cultivation of Oat. And Relative feed values (RFV) of MCOW were higher than single cultivation of Oat. Mixed cultivations of Oat and Triticale (MCOT) were got more production over 7 percents in the dry wight than single cultivations of Oat, but contents of CP in MCOT were not changed in all plots. And RFVs of MCOT were higher than single cultivations of Oat.