Abstract: Soaring demand and changing structure of meat consumption challenged China’s grain market. Predicting feed grain demand has strong policy implications for grain security in the context of agricultural “supply-side reform”. This study estimates the feed grain demand using the meat consumption data and the feed-meat conversion ratio. In addition, this paper also presents a projection on feed grain demand from the perspective of changing income elasticity, economic growth, demographic change and urbanization. Results show that the total feed grain demand will increase from almost 200 million tons in 2014 to 395 million tons in 2050; and the share of feed grain in total grain will rise from 32.52% to 58.79% during the same period. Soaring feed grain demand threats the self-sufficient rate and increases trade dependence, implying that feed security will dominate grain security in China in the near future. Our study provides valuable implications for the agricultural supply-side reform.