Abstract: From the socio-economic viewpoint,causes of environmental deterioration are analyzed,leading to the following conclusions:intuitonstically,the failure in market regulation and governmental intervention is the major cause of the deterioration.However,the basic reasons of the failure are:firstly,the ambiguous proprietorship of the natural resources;secondary,lack of uniform criteria for valuating natural resources;and tertiary,inadequate standards to assess socio-environmental costs of various projects of and policies for exploitation of the natural resources.In order to halt the trend of the deterioration,it is essential to uproot these problems.

Key words: environmental cost, environmental deterioration, natural resource, proprietorship, valuation