Abstract: The fact that species are not equally important for the functioning of ecosystems is now widely recognised. With the presumed significance of keystone species in ecosystems, it is assumed that if we can distinguish the keystone species of an ecosystem and the mechanism through which they affect ecosystem processes, we will have obtained the most useful information on the functioning of the ecosystem. This information would be of great benefit to managers, especially when the keystone species itself is a target for management. Thus when considering biodiversity conservation, the term "keystone species" has been introduced by conservationists and ecologists to protect ecosystem functioning more efficiently with the protection of keystone species. In this paper, we reviewed the advances in researches on keystone species, and concluded the possible approach to determine quantitatively the keystone species in an ecosystem, and the significant, but limited, application of keystone species in biodiversity conservation.

Key words: Keystone species, Determination of keystones, Biodiversity conservation