The coastal area of Hsinchu plain locates in the periphery of agricultural land-use. The coastal type of the area belongs to liman coast, that combines lagoons with offshore bars and spits. In general, there are rich biomass in the ecological region of lagoons. They offer multiple opportunities for the inhabitant living in study area to develop their various sustaining styles. These sustaining styles included fishery of alongshore, cultivation of oyster, shells gathering, saline making and port charges and so on. Bacause more and more lagoons, offshore bar and spits became tidal flat in study area, the sustaining styles had been changed from marine to land by degree. At same time, the carrying capacity of cultivated land rises gradually. Owing to the various and highly productive water district, the increasing gradually tidal flat and the rise of carrying capacity of land, even though over-population resulted from overloading of cultivated land the lineage clans could be still last and more prosperous than ever.