In a new era of development, China is undergoing a transitional period of dramatical improvement and adjustment. National development is dependent on land space and requirements for optimization of land space is inevitable in the transitional period.This paper focuses on the problems and representations of the transition, and the new requirements for optimization of national land space in the transition period from a comprehensive integrated platform of economic, political, social, ecological constructions and new-style urbanization aspects. Then it makes the following recommendations: first, spatial layout and allocation of resources should be optimized to boost the industrial upgrading, transition and quality development; second, government management in land space should be improved and public involvement should be promoted; third, development and protection of national land space and social economic growth should be planned as a whole to achieve a harmonious social, economic and ecological development; fourth, approaches to develop the land space should be optimized to better support the new-style urbanization and rural revitalization.