Desertification control has been facing severe situations in the interlocking area between cultivated land and gazing land in North China since the Qing Dynasty because of unreasonable land utilization. The paper analyzes the policies of all the previous governments to open up land, and examines the historical and geographical background and process by means of historical records. We consider that causes of the area of land desertification to extend are increase of farming migrants, the change of life style of Mongol and weather and land conditions. In order to control the spread of land desertification, we suggest the level of the government to make policies should be improved, the number of farming migrants should be controlled, the Government′s general and specifie polices should be actively publicized, and investment in agriculture should be increased.