Abstract: Intelligent manufacturing has become a developing direction of global manufacturing in the twenty-first century. So far, the research of intelligent manufacturing focuses mainly on the level of macro industrial policy and the level of technical application. However, quantitative analysis of intelligent manufacturing has not yet been carried out. Based on the patent documents of key fields of intelligent manufacturing in China from incoPat, the article makes a comparative study on the development of key areas of intelligent manufacturing in four cities (Beijing, Shanghai, Shenzhen and Tianjin) from the aspects of patent time trends, patent applicants cooperation, and technological hot spots. And on the basis of this analysis, the countermeasures and suggestions for further development of intelligent manufacturing in those cities are put forward.