After analyzing the background of air rights systems to come into being and research progress in western countries and China, the author points out we need to research four aspects to build up the layered utilization system of urban public land for construction based on air rights.

In the construction of urban public green space, there are game among the central government, the local governments, the citizen, the real estate interests.

The control on the standards of urban construction land is one of the most important traditional tasks of urban planning.

The purpose of the paper is to analyze differences of urban construction land.

This study appraises the recent integrated benefit in use of urban construction land in every province,from angles of economic benefit,social benefit,environment benefit and so on.

This paper summarizes the total progress on the planning study for the land out of urban constructing in several Chinese cities,then concludes the main study fruits in the turns of concept,target, content,method and implement.

The study on the land out of urban constructing (LOOUC) has began since 1990 s in China, and it can be regard as an important outcome in the transformation period of Chinese urban planning development.

In the rapid urbanization process of our country,the blind expansions of urban construction land use not only waste the land resources,but also damage the ecological environment of cities.