In order to systematically analyze the relationship between financial development, scientific and tech? nological innovation and marine economy in coastal areas, a comprehensive evaluation index system of financial development, scientific and technological innovation and marine economy is constructed. Taking the five repre? sentative coastal provinces or cities of Jiangsu, Shanghai, Zhejiang, Shandong and Guangdong as subjects, the comprehensive indexes of the three subsystems are calculated respectively. Then the coupling coordination de? gree model is established to analyze the coupling coordination relationship among the three. The study finds that the financial development index, scientific and technological innovation index and marine economic development index of the five coastal provinces (cities) all show a fluctuating upward trend, with only small regional differ? ences. The calculation results of the coupling coordination degree model show that the coordination level of fi? nancial development, scientific and technological innovation and marine economic system in the five coastal provinces (cities) has improved year by year, and has reached a good coordination level. This reflects that finan? cial development and scientific and technological innovation have effectively promoted the provincial marine eco? nomic development, but they have not reached high-quality coordination, and the coordination level of the three needs to be further improved.