China is a water-rich country in terms of rainfall and rivers' size, but its urbanization mainly occurs in the eastern coastal cities. The densely populated coastal cities intensify the water stress. To seal the gap between water demand and supply, many ways have been tested like water diversion projects, desalination plants and wastewater recycling plants etc. Different from these solutions, this paper discusses the strategy of coastal reservoirs in China's coastal cities. Its feasibility of using the available water is investigated and its water quality can be ensured if the second generation coastal reservoirs are applied. The results show that the water shortage problems in China coastal cities can be well solved if CRs are applied.