Based on the analysis of the problems of land surface processes research and global change, and the international background of studies on the global climate change, earth system science, sustainable development research, we suggested that it be the right time for promoting studies on land surface system science to disciplinary systems, which also presents a rare opportunity. The current studies on land surface processes have many problems, such as systemic integration being not enough between different surface elements, there being no complete, systematic structural systems, the lack of a reasonable, effective integration methods and means on studies on land surface processes, and the studies on land surface processes not upgraded to discipline research level. Through the analysis of scientific research and theoretical understanding of the land surface system in China, and the international urgent scientific needs of scientific research on land surface systems, we suggested that studies on land surface processes transit from focusing on elements of the land surface process to the systematic land surface systems science, which is also the focal point of future studies on earth surface processes. On the basis of the above analysis, the object and targets, the key scientific issues, the spatial and temporal scales, and research methods and means of the studies on land surface system science were pointed out, and the basic framework of studies on land surface system science were discussed. Data monitoring and analysis system, simulation and integrated systems, and decision support systems constitute the main line of the land surface system science. The core objectives of the land surface system science are meeting the needs of complex decision analysis on different spatial and temporal scales on land surface processes of scientific research and decision-makers through the systemic studies on land surface processes. Coupling and conversing between different spatial and temporal scales, the interaction between land surface circle with other earth circles, the complex issues-oriented critical process selecting from the system perspective, and coupling mechanism of human and nature are key scientific issues on the studies on land surface system science. Definition and scale conversion of scientific research in spatial and temporal scales of the surface system. Land surface system science should include a comprehensive and integrated research on surface monitoring of total factor, multi-source data fusion, process analog and simulation, and results analysis.