Abstract: The plant phytohormone cytokinin regulates numerous growth and developmental processes by regulating cell division and cell differentiation. During the past ten years, remarkable progress has been made to our understanding on the cytokinin metabolism, transport and signaling, mainly using Arabidopsis thaliana as a model system. In addition, substantial attentions have also been paid to crosstalks between cytokinin and other signaling pathways. According to our current understanding, cytokinin signaling is mediated by sequentially transferring a phosphoryl group in different members of a two-component system, referred to as phosphorelay. The two-component system may also act as a module linking cytokinin and other signaling pathways. Most known members of the two-component system are functionally redundant, but also show distinctive function in the regulation of a variety of developmental processes. In this review, we summarize our current understanding on cytokinin metabolism and transport, and discuss in detail on recent advances in cytokinin signaling as well as its cross-talks with other signaling pathways. We also make prospects on possible improvement of important agricultural traits by manipulating the cytokinin network.