In the last decade, biodiversity became a central concept of ecology, as important as the concepts of sustainable development, right for future generations, global changes for instance. Biodiversity received a recognition through, the Brundtland report (1987) and the Earth Summit of Rio de Janeiro (1992). Protection of biodiversity represents nowadays a ethical and political obligation.If the concept is rather clear and is applied at three levels, genes (intraspecific and interspecific), species and ecosystems, if we know that the diversity is unequally (...) distributed, concentrated in tropical areas, if it is clear that ecologists have still the immense task to describe this diversity, the ethical foundations of protection of biodiversity are unclear by the high variability of concepts in use.Environmental ethics and protection of biodiversity are often placed in aKind of antagonism, between technocratism or neo-liberralism and fundamentalism of Nature or even eco-fascism. But, in fact, there is no need for an “either-or” attitude, for an “all-or- nothing” thought for an opposition between “natural” and “artificial” or between anthropocentrism and biocentrism: we have here perhaps not incompatible opposites but poles on an spectrum allowing for many degrees.We must manage that the needs of the present are met without compromising the ability of future generations to meet their own needs. Sustainability is:* socially desirable, fulfilling people's cultural, material and spiritual needs in equitable ways, *economically viable, paying for itself with costs not exceeding income, ecologically viable, maintaining the long-term viability of supporting ecosystems.The “business-as-usual” activity resulted in low rigorous protection of biodiversity, we need an increasing part of ethical considerations in the environmental discussion. (shrink)