Abstract: This article focuses on the concept and research method of Marine ecological carrying capacity,builds the evaluation index system of ecological carrying capacity by analyzing the multicollinearity indicators,which was overlap of indicators of the standardization of dimensionless processing of raw data by eliminating redundant indicators.Then AHP,entropy and "yaahp"software were used to calculate the final weight to reduce the error of the artificial calculation to ensure scientific and reasonable index weight.Finally the state space model was used to analyze the marine ecological bearing capacity.The results show that the Nantong ecological carrying capacity showed a reduce trend of fluctuation change,have a good condition 2009-2010,the basic state 2011-2013,the bad condition 2014.