Abstract: Based on Niche Theory, from the perspectives of niche strength, niche width, niche overlap, give a comprehensive analysis of the marine industry niche present status, using specific biology quantitative models: Shannon-Wiener index and Pianka formula etc. Calculation results can well explain marine economic development situation and overall features in coastal provinces. Based on the common isomorphic phenomenon, the 11coastal provinces were grouped by the intensity and width characteristics to form the corresponding competitive strategy. This will provide a new reference and inspiration for improving the development of marine economy layout and strategic planning.