Abstract: Ca²⁺ is an important secondary messenger in signal transduction in plant cells. When plants are exposed to fluctuating environmental conditions Ca²⁺ signals are perceived and decoded by Ca²⁺ sensors (CaMs, CaMLs, CBLs and CDPKs) to elicit the expression level of related genes. Calcium-dependent protein kinase (CDPK) is a Ca²⁺ sensor playing a pivotal role in plant development, pollen tube elongation and responses to abiotic and biotic stimuli. It has the unique ability to directly transmit cytolic Ca²⁺ signals to downstream phosphorylation events in diverse substrates which can mediate interaction with 14-3-3 proteins to modulate protein functions. Most CDPKs have significant subcellular distribution, allowing them to “feel” local Ca²⁺ concentration and to act specifically with their target cells. 14-3-3 proteins are highly conserved in eukaryotic cells, which in most cases need to bind to different targets and be phosphorylated to modulate their activity. Through protein-protein interactions, 14-3-3 proteins are involved in many significant physiological processes in plants. Recent studies have revealed that the role of CDPK in phosphorylating sites in mediating 14-3-3 protein binding to form CDPK/14-3-3 complex, and have also highlighted the role of the CDPK/14-3-3 complex in regulating primary metabolism, plant hormone synthesis and flowering. In this paper, CDPK structure, subcellular localization, target protein, biological functions, especially the cross regulation between CDPK and 14-3-3 and their synergistic effect in plant signaling pathway will be discussed in depth. Our study aims are to provide a reference and indicate new directions for future CDPK research.