Watershed partitioning is the base of watershed management， water resources survey， water environment pollution monitoring， and water ecological plan. But， there are some problems in watershed partitioning for flat terrain. Taking Yantai City as an example， the ecological watersheds were extracted from DEM， corrected based on type of land use， and then classified as 23 first class watersheds， 93 second class watersheds and 550 third class watersheds. The watersheds extracted from DEM showed the problem of line boundary in the coastal， lake and paddy field areas， which would be corrected based on type of land use. The ecological watersheds were extracted at the 3 classes， and there are 537 ecological watersheds in Yantai City. The results show that it is feasible to extract ecological watersheds from DEM based on type of land use.