Abstract: To build up a patent map with patent documents has been one of important means to supervise and realize the developing status quo and trend of technology. The status quo of the research on the patent map at home and abroad is analyzed, the function of patent map is summed up, and a new visualization method for a patent map which represents patent analysis results with considering both structured and unstructured items of each patent document is studied by the adoption of the k-means clustering algorithm and semantic networks; the concrete steps making a patent map which gives a clear and instinctive insight into the targeted technology are suggested.