To reasonably assess the current development situation and spatial distribution characteristics of China's port industry and clarify the advantages and disadvantages，this paper takes 61 coastal cities in 11 provinces as research objects，calculates the output value of China's port industry in each coastal city based on the input-output basic flow table and related methods，and analyzes the current situation from the perspective of total volume，industry and city contribution，and further adopts the kernal density estimation method to specify the spatial distribution characteristics of China's port city and port city industry.The results show that the port industry is more developed in China's coastal cities，and the output value of port industry in more than 30% of the cities is close to or beyond 100 billion yuan，among which the Yangtze River Delta and the Pearl River Delta are the most densely clustered.61 coastal cities can be divided into 4 levels.