ABSTRACT
To meet the requirements for the development of marine resources and military operations, divers usually dive deeper than the depth at which narcosis is present during air diving.Under this condition, heliox is required for this div-ing.Sofar, some countries have developed their own decompression tables for routine heliox diving.The best-known is tables from USA and France.In the preceding century, tables of Former Soviet Union and France used for routine heliox diving were introduced into China.On the basis of both types of tables,Chinese Navy developed their own tables for this purpose. In this paper, we summarized the characteristics of these tables from 5 countries and compared them in terms of structure, oxygen use, total decompression time, first stop and other features.This may provide a basis for future modification of ta-bles used in China and the development of new tables for routine heliox diving.