During the past several years, functionalized alkylidenecyclopropanes (FACPs) have attracted intensive attention in synthetic chemistry. Many interesting transformations of FACPs have been developed to synthesize a lot of structurally diverse and valuable polycyclic and heterocyclic compounds. This review will classify FACPs into aryl-FACPs, alkyl-FACPs and ring-FACPs for the first time, and recent interesting chemical transformations in these research fields will be included, respectively, from 2011. Moreover, we will pay more attention to the clarification of the reaction mechanism, in which the C-C bond cleavage of alkylidenecyclopropanes (ACPs) will be emphasized.