The two essential terms in environmental sciences - dematerialization and decoupling - have always been controversial. This study aims to trace the evolution path on the methodologies, the evidences and the policies, and to reflect on the implications of the development. We specifically present several classical definitions so as to summarize the similarities and differences thereinafter. Several commonly used methodologies, which are employed for evaluating the levels of dematerialization and decoupling, are discussed. As expected, the empirical evidences rarely support the absolute dematerialization and decoupling, which challenge the relevant policies implemented worldwide. In this context, the rebound effect, which is regarded as the main obstacle, is necessary to be examined in the various sectors and areas. However, the results of the rebound levels are far from unanimous. This article has a further discussion on the possible direction for the inconclusive debate in a broader perspective.