To promote healthy development of coastal container ports in China, concentration was applied to analyze the evolution of market structure of container port industry. The outcomes show that the market structure of container port industry in China developed from oligopolisticⅠtype to oligopolistic Ⅲ type in these 30 years. At the same time, the concentration presents a decline trend, which indicates that the market structure will develop to oligopolistic Ⅳ type. Comparing with the United States of container port concentration, it is found that the concentration of container port in China is slightly higher than that in the United States in recent 10 years. The market structure in China and the United States are both oligopolistic Ⅲ type. However, the container throughput in China is 3.59 times of that in the United States, and the average throughput of top 4 ports in China is 4 times of that in the United States. The transport pressure of container ports in China is significantly greater than that in the United States. Too much transportation pressure will bring corresponding negative impact for port and port city. Therefore, the container port concentration in China will further decline under the effect of peripheral-port challenge.