Based on the theory of the diamond model competitive impact factors, we select China’s foreign trade cargo throughput of the ports, the volume of transportation, exports volume of goods, the amount of ocean shipping and the degree of openness of trade in maritime services from 2001 to 2010 for empirical analysis. The results show that the increase in the domestic market demand and the degree of openness can improve exports of China’s maritime services. Based on the empirical results, we suggest that China increase the proportion of domestic shipping amount, adjust its open shipping strategy and improve the competitiveness of its maritime industry.