The ecosystem services are material base and natural capital for sustainable development of human being. Valuation of ecosystem services is favorable for people realizing the importance of natural ecosystem to human being, and considering its long-term influence on sustainable development of human society when making decisions. Besides, it is an attempt of ecology, geography and other natural sciences to influence social decision process by economic methods. The Value of the World's Ecosystem Services and Natural Capital, written by Robert Costanza et al., in 1997, is generally regarded as a masterpiece for the research of valuing ecosystem services. However, the classifying standard of ecosystem services, the method of various services summation and the purpose for static global value, had confronted many criticisms. Still to now, accurately valuing ecosystem services is not easy, because of the complexity of natural ecosystem, the weak capability of economic system to pricing ecosystem services and the lack of more study in this field. Based on the criticisms summarizing and comprehensive analysis, further study suggestions of ecosystem services valuation is presented: multi-scale integrated and community participation applied in evaluation, dynamic changes of material value and intangible value of ecosystem services, investigation and simulation studies of the marginal value when ecosystem services changed, associated with related areas like ecological compensation research, and research on the market-oriented evaluation of ecosystem’s intangible values.