Abstract: Biodiversity is a kind of precious natural resource and becomes cornerstone of mankind society's sustainable development．This paper at first introduces the present situaiton of the loss in the world's biodiversity,analyses that the source resulting in biodiversity to lose is not in species and habitats themselves,but in the current e- conomic system leading to the economic action of mankind,especially the price system in which doesn't complitely,exactly reflect all kinds of value in biodiversity．Finally,putting forward some economic measures of conserving biodiversity．