Abstract: G -protein mediated signaling system is the most common signal transmission in cells. G-protein coupled of signal transmission system consist of G-proteln coupled receptor （G-protein coupled receptors, namely as GPCRs）, G-protein and effector. In 1977, Ross and Gilman confirmed G-protein could be used as cell receptor and effector between the converter. And a large number of studies found that the G-protein coupled signal conduction system existed in plants and animals widely. The role of G-protein and GPCRs in the cell conduction was mainly discussed.