Land resources, as part of important natural resources, are the basis of existence and development of human society, which is also a key to the sustainable development of society. Increasing human population associated with decreasing land resources is the basic situation of China, which will consequently lead a fast conversion from farmland to construction land due to the speeding up industrialization and urbanization process in China. In this case, a full understanding of the reasonableness of regional land use structure can promote effective allocation of resources and development of regional economy, which may result in a positive impact on the regional population bearing capacity and sustainability, in addition, a profound impact on the coordination relationship between human being-arable land resources, human being-environment with the economic development can be anticipated. How to reasonably allocate the limited land resources according to the sustainable development of regional socio-economic conditions, ensure the land supply to meet the requirements of human production and live sustainable develop, ease the contradiction between people and land, is an important task in front of us. Sustainable development has been considered the most suitable strategy of human development, which requires that the regional population bearing capacity must be within the range of earth′s ecological carrying capacity (most appropriate standard). Therefore, assessing sustainable development is a hotspot and foreland of sustainable development research. Eco-footprint analysis method based on quantitatively measuring natural resources utilization is such a new approach to evaluate sustainable development. This method mainly includes two aspects: first, the development sustainability primarily depends on the status of ecological resources usage and consumption and the life-supporting capacity of ecosystem resources; second, all human beings have the equal right of using ecosystem resources, thus the quantitative assessment and comparison of different regional development sustainability and the specification of corresponding responsibility can fulfill the realization of eco-ethics fair. This paper calculated the sustainable capacity and load factor in Lulong country to show the scale of crop land and building area that the regional society and economy sustainable development can hold. It also explored the potential transferring relationship between crop land and building area based on the standards of available transformational quantity. The results showed that: (1) the ecological footprint, capacity and ecological deficit per capita in Lulong county are 17667 hm2, 0.5381 hm2 and 1.2285 hm2 respectively, which are associated with an average annual growth rate of 340%, 1.73% and 4.29%; (2) from 1997 to 2008, ecological footprints of crop land and building area are growing, where the annual ecological footprints of farmland and building area are 0.4621 hm2 and 0.0134 hm2 per capita, and the former accounts 26.16% of the total ecological footprint; in comparison with ecological footprint of farmland, a lower requirement by the ecological footprint of build area is found. The capacity of farmland and building area are 0.3831 hm2 and 0.1447 hm2 per capita, accounting 71.20% and 26.89% of the total capacity, respectively, and the later is associated with an annual increasing rate of 0.63%; (3) the gradual declining capacity of crop land sustainable development is lower than the current practical area, and a negative load factor of crop land is identified, which indicates that the requirement of sustainable development cannot be met；The capacity of building area is with certain variability and the average value of load factor is greater than 2.20; (4) from 1997 to 2003, the requirement of crop land was still lower than the sustainable development need, but the available transformational quantity had dropped sharply to 1889.46 hm2; from 2004 to 2005, although this quantity had exceeded the sustainable development requirement, it still can be met through restoring aborted building areas; from 2006 to 2008, the requirement cannot be met even if all aborted building areas have been restored to arable land.