Basic components of values of biodiversity are analyzed. The methods of estimation of various benefits of biodiversity conservation are exposed with an emphasis on the contingent valuation methods. On the basis of the prepared by the author questionnaire various Willingness-To-Pay (WTP) values are estimated for the non-use value benefits. Various estimations of the basic components of the value of biodiversity are commented based on case study of the Bulgarian Danube islands. The results demonstrate relatively high WTP in favor of restoration of natural forests on the Danube islands, which is expected to pull the development of tourism and recreation, commercial and non-commercial fishing and hunting. It is expected that the growth of revenues from activities stimulated by biodiversity conservation as tourism, recreation, etc. will compensate the reduction of revenues from the reduced logging of timber from the poplar plantations.