Due to rapid growth of economy in the world, which results into shipping goods flow one place to another in large volumes, the competition becoming more intense among ports. Shanghai port and Ningbo-Zhoushan port are the two most important ports in the Yangtze River Delta and have the same economic hinterland, inevitably there is a heated competition between the two ports. This paper using the approach of SWOT to analyze the issue of competition and cooperation between the two ports, and then makes an analysis of their Co-opetition strategies by employing the analyzing methods based on the Game theory. Finally, it puts forward some strategies to enhance the cooperation between the two ports.