Abstract: Regional ecological risk assessment (ERA) was used to forecast and evaluate unfavorable ecological environment evolution trend with long time scale, large spatial scale, multi-medium source and complex-type pollution. As an efficient tool for sustainable environmental management, regional ERA had become a hot field in environmental science and environmental protection. Strategic environmental Assessment (SEA) usually, from the viewpoint of environmental management, carried out forecast and evaluation of the potential environmental effects caused by government decisions and development activities. It focused on long-term and accumulative environmental effects in key ecosystem functional units and sensitive environmental receptors and the long- and medium-term ecological risks. Regional ERA and SEA had strong consistency in their aims, targets and evaluation scales. Regional ERA could be important methodology and content of SEA. As the ecosystem complexity and ecological balance changes determined the complexity and uncertainty in the process of ecological assessment, especially when it was not enough for the study of the non-chemical risk sources, the research on high levels, e.g. community and ecosystem, of risk assessment, including assessment terminal choice and ecological effect quantitative evaluation method, should be strengthened.