The tip-enhanced Raman spectroscopy (TERS) has drawn much attention from the academic community due to its high spatial resolution and detection sensitivity in the last decade. The TERS method provides a powerful tool for the nano-material science and life science. It makes nano- spectroscopy come true. The basic principles of TERS are briefly described,and the configuration,design method and evaluation criterion of TERS systems are discussed. The new applications and research of TERS are introduced,and the frontier topics,key technical issues are analyzed.