Abstract: The third national land survey in 2019, has been fully developed, and the map signs of land type is the emphasis and difficulty in the work. Based on our experience in the implementation of the multiple projects in the south of China, this paper has developed a set of rules and experience of land category identification aiming to solve the problems with wrong judgment easy to make in the work of the three map signs of land type. They are soil moving, construction land and idle land, according to the analysis results from the comparison of images, scene photos and the basis of asserting releasing by country. It helps people to make the class identification quickly and accurately in the third national land survey,avoiding rework and revising of the database, so as to improve the work efficiency of the operation team and the quality of our work in the third national land survey.

Key words: the third national land survey, job classification, soil moving, construction land, idle land