Abstract: External fringe space is easier to be ignored in the plan of open space of a waterfront building，but it is also one of the most frequently used forms of space under the unconscious． Taking Wuzhen for example， and starting from the analysis of the concept of the edge space，it was analyzed all kinds of edge spaces formed between the building and inner street，building and building，as well as building and river，in order to develop the beneficial fringe space of the waterfront building reasonably，and enrich the shape of its space.