Abstract: The demand and application prospects of marine radioactive risk assessment in China have become increasingly prominent with rapid applications of nuclear technology such as coastal nuclear power plants. According to the iterative thinking of ecological risk assessment, the methodology of radioactivity risk assessment, the model of relative risk assessment and the application of sensitivity assessment in the regional risk assessment, in combinations with the current situation of marine radioactivity monitoring and ecological impact evaluation in China, this paper proposes preliminarily a comprehensive framework for marine radioactive risk assessment based on grading evaluation, which is composed of a three layer assessments including risk screening, risk analysis and risk decision. Based on the relative risk model of radioactivity in sea areas, the established risk decision making method provides assessment support under different time periods, different working conditions and different data. Finally, due to the lack of basic data in marine radioactive risk assessment in China, it is necessary to strengthen the survey of marine radioactive baseline and the researches of marine radioactive ecotoxicology for scientific and accurate assessments of marine radioactive risk.