Abstract: A subsea tunnel suffers the long-term impact of chloride corrosion, and with a required design service life of 100 years or more, many more studies of durability design are needed than for normal tunnels. Current study of subsea tunnel durability focuses on material selection and the mix proportion of reinforced concrete structures. This paper gives a detailed analysis of environmental conditions, relevant code specifications and durability design principles for subsea bored tunnels in chloride environments and proposes the concept of paying equal attention to the durability design and bearing capacity design as well as reserving enough space for later restoration. The analysis shows that high-strength high-performance concrete should be adopted for subsea tunnel linings in order to improve concrete density and to resist seawater corrosion, and the limited groundwater drainage principle should be adopted for mined subsea tunnels to ensure effectiveness of their drainage systems.