After reviewing the related literature，we summarized the connotation，types，system construction，technological process，and focus on the pre-warning system of land security

and the general idea applicable to Chinese national conditions was further discussed. In this article，using the goal of early-warning method，the case of cultivated land security in Guangzhou City was demonstrated. Totally the situation of cultivated land security in Guangzhou. City becomes worse. Although some progresses have reached，there are still a large number of actual issues to be studied further. It is necessary to make a unified technical regu- lation to solve the existing problems.