Abstract: Based on the cross-language comparison, this paper discusses the form-meaning relationship, mechanism and hierarchical system of middle construction under the theory of Construction Grammar.Firstly, we extract two basic elements that form middle category, namely the inherent property and external force, and then summarize the form-meaning pair patterns of middle construction among Indo-European languages.Since middle construction is the integration of property-triggered event and action event, we reveal its dual information packaging mechanism with property-triggered event as foreground and action event as background, based on which we prove the structural rationale of middle construction that distinguishes itself from other related constructions.Finally, this paper establishes middle construction hierarchy systems in English and Chinese and compares their similarities and differences, thus providing a new thinking on the theoretical status of Chinese middle construction.