Abstract: CDPKs play important roles in the plant calcium signal transduction. Based on plant calcium signal transduction, and structure and biochemical properties of CDPKs, potential regulatory roles of CDPKs in gene expression, metabolism,traffic of ions and water across membranes,the dynamics of the cytoskeleton, stomatal movement, as well as growth and development were summarized. Recognitions and challenges in CDPK studies were also put forward.