Abstract: According to the degree of concealment, the main origin type and the profile form of hydrocarbon traps, a new classification for subtle traps has been made on the basis of predecessors work. It includes not only stratigraphic and lithologic reservoirs, but also paleo-structure trap reservoirs, syncline reservoirs and low permeability reservoirs being susceptible to damage, etc.. It is helpful for petroleum explorationist to expand research fields and to apply different methods by different types of subtle traps in hydrocarbon exploration.