Background　Triggering receptor expressed by myeloid cell（TREM） belongs to a kind of immunoglobulin superfamily. In the central nervous system， TREM-2 is mainly expressed in microglial cells. Some investigations indicated that the activation of TREM-2 could attenuate microglial activation， decrease the secretions of pro-inflammatory factors and attenuate the degree of neuroinflammation. Therefore activation of TREM-2 may induce a neuroprotective effect.　Objective　The aim of this review is to discuss the role of TREM-2 in the central nervous system（CNS） diseases for exploring a novel treatment by reducing neuroinflammation.　Content　At the beginning， the characteristics of the TREM family were introduced. And then the roles played by TREM-2 were discussed in many CNS diseases. Finally， we analyzed the potential mechanisms of TREM-2 in neuroprotections.　Trend　TREM-2 may become a novel therapeutic target for inhibiting inflammatory responses in CNS， which may provide a different direction for the treatments of CNS diseases.