Abstract: Land conversion from rural to urban is a cost for realizing the urbanization and industrialization, and it has become a common phenomenon in the process of urbanization and economy development in developed countries or developing countries. It is very important for China to protecting farmland because it has many populations and little farmland. However, Land conversion from rural to urban will being in the process of urbanization. So, farmland protection is still a problem. On the basis of analyzing other researches, the paper thought the principle parts of land conversion from rural to urban are local government, peasants, enterprises, and inhabitants, the driving forces are systems, economy, location, urbanization, and concept of value. Farmland is converted from rural to urban under mutual action of above the principle parts and he driving forces. Finally, Some countermeasures such as establishing the scientific viewpoint of development are suggested in this paper to control the loss of farmland.