Field-effect transistor (FET)-based biosensors (BioFETs) have undergone great progress especially in the last decade, since they were first realized in 1980. Recently, BioFETs have become one of the most important branches of biosensors. This paper briefly reviewed the operating principles of BioFETs and summarized the improvement and application of BioFETs, finally, the future prospects of BioFETs were discussed with 126 references.