Abstract: The assessment of supply and demand of ecosystem services can help identify regional equilibrium, ecological trade-off, management, and compensation. It is one of the key issues in ecosystem service studies. We collected literature on the assessment methods of ecosystem services. Based on the existing studies, the assessment methods were classified into four categories: ecological model, value assessment method, participation method, and empirical statistical model. These four types of methods are mainly used to assess service supply, but seldom be used in studies on demand assessment. Ecological model and value assessment method are applicable to a wide range of scales, from the local scale to global scale, while the participation method and empirical statistical model are usually used at small and medium scales. Compared with the other three types of methods, ecological model requires more types of data, higher requirements ofinput data, with higher evaluation accuracy. Ecological model has more advantages in spatial scale, data acquisition, and applications. Finally, we suggested that three aspects deserved more attentions in the future, including: building a diverse and standard supply-demand indicator system, strengthening the accuracy of ecosystem service assessment, and strengthening the integration and development of different models.

Key words: carbon sequestration potential., Gansu Province, carbon storage, plantation, carbon density