Complex interventions are commonly used in health and social care services, public health practice, and other areas of social and economic policy that have consequences for health. Due to the multiple components of interventions, the complicated mechanisms of change, the diversity of the population involved, and the interaction between the intervention and the context in which it is implemented, the appropriate development and evaluation of complex interventions has become increasingly critical. The UK Medical Research Council published a framework for developing and evaluating complex interventions. The aim of this article is to introduce and interpret the framework to provide guidance on the development and evaluation of complex interventions for domestic researchers.