The historical and cultural landscape or blocks of small towns are facing the outstanding protection and utilization problems, which includes the contradiction between protection and development on one hand, and the insufficient economic benefits of direct use and the limited protection funds on the other hand. Therefore, it is necessary to determine its function in the small town. The geographical perspective has unique advantages for the current few studies on the relation between them and the entire city which they are in. This paper takes the Lougang, a World Water Conservancy and also a Cultural Landscape Heritage, in Huzhou, Zhejiang Province as an example. It tries to use the 'horizontal analysis' of geography to illustrate the importance of protecting the "area" to the overall city of Huzhou. The conclusions of this paper are as follows. First, geographical perspectives can play an important role in helping determine the functioning of cultural heritage area. Only by observing the "flows", people can understand the function of Lougang Area in the past and present, and then can provide a reference for the functioning of the area in urban and rural planning. Second, Lougang has multi-functions in the Master Planning of Huzhou. The rank of those functions could be measured by the benefits brought by Lougang Area to other functional areas. Water conservancy and cultural functions rank the first, followed by leisure tourism and agriculture.