The objective of publishing this book is to let the general public have a better understanding of the food security situation in China and better comprehension of the merit of allocating land through market mechanism. In addition, it makes the public aware of the inefficiencies of current government regulated land system.As a populous country in the world, China emphasizes too much importance of food to ensure people's sufficient consumption. There is a national policy to protect farm land, farm land protection refers to 18 hundred million mu of farmland which is specifically designated for food production only. Unirule defined the national food security as the capability to solve food shortages, and calculated the gap between food supply and demand. Two approaches can be used to solve the above food gap. Food security problems will not happen under situations of free trade and factors substitution in market economy, substantial storage and foreign exchange income. In modern China, food insecurity or great famine only happened in planned economy. To link tightly farm land size and grain yield and even food security is baseless both in theory and practices. The previous red line of 21 hundred million mu was already broken through. The current red line of 18 hundred million mu will also be broken through, in view of the process of industrialization and urbanization. In fact, farm land protection should focus on protecting the employment right of peasant in land.