The membrane potential of a cell is produced by the difference between intracellular and extracellular ion concentrations, which can be categorized into either resting potential or action potential. Voltage clamp and patch clamp are the main techniques to detect and record the membrane potential. And the electrode in the voltage clamp and glass tube in the patch clamp can stimulate the cell membrane and can’t monitor or record the potential online. Cell-field effect transistor is a kind of sensor for membrane potential detection which controls the leakage source current of the device at the grid, so as to sense the membrane potential of cell. It is a new technology of membrane potential detection and record, and its advantage is that detecting without stimulation to the cell membrane, and monitoring at real time for a long time length. And it can be widely applied to the fields such as scientific research, drug development, medical device, inspection and quarantine, environmental protection, public security, and so on. This paper introduced the structure, transfer characteristic, equivalent circuit, preparation technology of the cell-FET sensor, and application in action potential recording, real-time monitoring of cell growth, monitoring of exocytosis, and detecting of tumor biomarker.