Abstract：At present，many subsea tunnels are under construction or design in China，and the minimum rock cover is one of main issues in subsea tunnel vertical cross-section lining design；and the subsea tunnel cost and safety are directly governed by the minimum rock cover. The determination method and criterion for the minimum rock cover depth is studied. Different methods determining the minimum rock cover depth are analyzed；and the factors of the different methods for the minimum rock cover are researched. The idea and method to determine the minimum rock cover depth of the subsea tunnel by the weight factors are also obtained. At last，combining with practical subsea tunnel engineering，the minimum rock cover of the Ningbo Xiangshan Harbour subsea tunnel by the above methods is analyzed.
