Abstract: This article summarizes the research progress of international marine environmental radiation quality assessment considering the actual needs of China's marine management and proposes to divide the marine environmental radiation quality into four levels, which indicate that from level 1 to 4 the environmental radioactivity level is in the background range, exceeds the background range with no harm, exceeds the limit of radiation dose for public and exceeds the limit of the marine biological radiation dose, respectively. The calculation methods for determining the derived concentration limits (DCLs) of radioactivity for each level are demonstrated. The first-level DCL is based on China's marine radioactivity background survey data, and determined with statistical analysis methods. The second-level DCL is derived from the annual dose limit for seafood consumers specified in national Sea Water Quality Standard (GB3097-1997), the concentration factors (CFs), the dose conversion coefficients (DCCs), and the seafood consumption rate, etc. The third-level DCL is derived from the commonly used radiological dose rate limit for marine organisms, CFs and DCCs, to protect marine organisms from the adverse impacts on the population level. Finally, this article compares the DCLs with the current national standard limits for several radionuclides in seawater. The results of this research will help to evaluate the routine monitoring data and also provide technical support and reference for marine management decision-making.