In the domain of land science, the construction of a discipline system is an important issue from 1980s, and has been a hot topic in recent years. However, the construction of land science discipline system is still immature and imperfect, for which the deviation from the concept of land is an important reason. The construction of land science discipline system should always take the concept of land as foundation and core.Land is a product of the combined action of natural factors and human factors, a result of the combined action of natural movement and human activities, and so is a natural and human complex. Complex is the scientific kernel of the concept of land, and land science takes land complex as a research object. The discipline uniqueness of land science lies in researching land as a complex and focusing on factors interaction and comprehensive performance(especially at small and medium scales). From this, land science faces unique problems, and produces distinctive theories and methods, and so it can form a relatively independent knowledge system. The research on land complex has three levels, including the basic level, the applied level and the engineering level, serving respectively the human practices of cognizing land complex, utilizing land complex and modifying land complex. Accordingly, the discipline system of land science can be built on three modules: the basic research module, the applied research module and the engineering research module, which are respectively the foundation part, the main body and the support part of land science. According to different research perspectives, methods and contents on land complex, the three modules of land science as a first level discipline can be further divided into six secondary disciplines, more than 30 tertiary disciplines and more than a hundred of research directions. In the research on land complex, all the secondary and tertiary disciplines of land science can be given proper position. Among them, the basic research module has two secondary disciplines: land resource and land utilization, which respectively researches the natural attributes of land complex(land natural complex)and researches the human attributes of land complex(land human complex), both using methods including survey, categorization, regionalization, evaluation, history and others. The applied research module has two secondary disciplines:land management and land administration, which respectively researches the production and operation activities(pursuing market values)of market bodies using land complex and researches public administration activities(pursing public value)of public organization to the utilization of land complex. The land engineering research module has two secondary disciplines: land reclamation and land protection disciplines, which respectively researches land reclamation projects on land complex of unused, difficult to use or inefficient use, and researches land conservation projects on land complex of potential and concrete degradation, damage or contamination. Land science is a comprehensive discipline, which at the same time has the attributes of natural science, social science and engineering science. As the main attribute, social science is the main academic position and the most promising development field for land science. Land science is also a growing discipline in China and it is faced with urgent tasks such as expanding academic community, enhancing discipline cohesion, and improving discipline recognition, and international promotion.