Abstract: SCA(Site Catchment Analysis)has been widely used in studies of prehistoric economy and human behavior. This paper developments an empirical onsite perspective，rather than the deductive offsite approach，to investigate the plant resource catchments of two sites in different contexts. The first case is Tianluoshan site，a Hemudu culture settlement(6900～6500cal.aBP.)located in the lower Yangtze region. Our study shows that early rice cultivation was developed alongside gathering activities for an extended period；    a spatially wide but specialized，pattern of seasonal gathering for storage is the main characteristic of this subsistence system. Site location may reflect a strategy to obtain a wide variety of resources，because most of plant food resources could be obtained within a oneday catchment. However，some may have been further away than a 12 hours walking distance，in which case shortstay camping must have been involved，which would also have allowed further hunting. The second case considers Yangshao culture settlements(6000cal.aB.P.)along the upper Ying river valley in the central plain of China，with Yuanqiao site as the focus. Although there would have been various wild food resources within a two or three hours walk catchment，Yuanqiao site has a much more focused and spatially narrow use of its landscape. The shrinking of site resource catchments，the modification of surrounding landscape and the new settlement relationships in terms of land use and resource sharing with other sites，are all characteristics that can be associated with a typically agricultural settlement. Based on these two case studies，we can suggest that agriculture represents a change in landscape and how it was used rather than simply the presence or absence of domesticated plant remains. SCA provides a new approach to understanding the emergence and development of agricultural societies and the interaction of communities，whether agricultural or not，with their surrounding landscape.