Abstract: Phospholipases D (PLD EC 3.1.4.4) hydrolyze phospholipids,which are the backbones of biological membranes. The activities of these enzymes not only have an important impact on the structure and stability of cellular membranes but also play an pivotal role in regulating many critical cellular functions，including cellul ar signal transdcution, vesicle trafficking, cell proliferation, hormone action，celluar backbone formation, defense responses，seed germination and sensescence. In recent years，the role of PLD in transmembrane signal transduction has become a new research topic. This article gives a brief introduction on PLD gene structure, subcellular distribution, expression and the role of gene products in plant cellular signal transduction.