Abstract: Exactly measuring the degradation degree of ecosystems is the basis, precondition of restoring ecosystems. At present,degradation degree is usually analyzed qualitatively.In this paper,quantitative classification method was used to study the degradation degree of ecosystem in hilly region of western Liaoning,which was measured by the degradation degree of habitat.The result shows that the habitat in the northern slope of mountains has been degraded to certain stage between shrubbery, pioneer tree forest,which provides theoretical basis for vegetation restoration practice. Moreover,the result is beneficial for studying the degradation degree of ecosystems in other regions or of other types.