Abstract: The development of the unconstructed area is an important means of urban development. Before the development,the compliance of the land,the size of the developable area and the value of the land are the basic conditions to measure whether the area has the development potential. On the basis of the results of the third national land survey,combined with the UAV tilt photogrammetry technology,a comprehensive survey is conducted to determine the current land use status,land ownership status,and land supply status of the undeveloped area. By means of field survey,office processing and other means,the immediately developable land area of the unconstructed area is basically determined,and its land valuation is estimated,which provides a reference theoretical basis for subsequent land development.

Key words: unconstructed area, immediately developable land survey, value estimation