Regolith is a loose accumulation layer formed by weathering over land surface. It is a natural structure for storm water storage, and has significant effects on the management of water resources in watershed. Based on recent research home and abroad, the Complex Open System Theory was employed in the present study to analyze the ecological mechanism of regolith stormwater storage. The material composition and spatio-temporal structure of regolith with respect to stormwater storage are discussed in this paper. The stormwater storage functions of regolith, including water collection, storage, purification, nourishment, and supply are explained, and the ecological relationships between regolith and watershed environmental elements, such as the topography, habitat, geology, soil, atmosphere, energy, and human activities were explored. This study shows that: (1) the storage characteristics of stormwater of the regolith are crucially influenced by its unique matter and spatio-temporal structure. If the stormwater storage function of the regolith could come into play, this water could change into healthy "living water." The spatio-temporal variation of the material composition and structure of the regolith in different watersheds is significantly distinct, and the functional mechanism of the regolith stormwater storage is extremely complex. The use of quantitative methods to study these mechanisms is not feasible; therefore, Complex Open System Theory should be employed. (2) Regolith is a subsystem of watershed, which is connected to and interacts with other environmental features in the watershed. The earlier methods of regulation that used the "Drainage Paradigm" to solve problems partially in order to improve the whole watershed systematical condition are no longer applicable, since these methods do not adapt to later ecological studies of regolith stormwater storage. It is much more likely that new systematical problems would arise. (3) The watershed is considered to be a complex open system, and watershed ecologists in other countries have put forth the "Ecostructures" concept. It emphasizes the development of the watershed system's ecological capabilities. Therefore, the focus of the studies on watershed stormwater storage should be expanded from the Soil-Vegetation-Atmosphere continuum to the Regolith-Habitat-Energy continuum. The present study suggests that we adopt "Learning by Doing" management methods for watershed adaptability, which would be an important direction for research on the management of watershed regolith stormwater storage in future.