Background　Triggering receptor expressed on myeloid cells (TREM)-1 is mainly expressed on neutrophils and monocytes /macrophages. It induces neutrophils and monocytes to increase the release of proinflammatory factors such as TNF-α, IL-1β, which plays an important role in the ampli -fication of inflammation.　Objective　To explore the mechanism of TREM-1 in neonatal lung injury.　Content　The sources and functions of TREM, the role of TREM-1 in inflammatory responseand the role of soluble TREM-1 in neonatal diseases, such as premature diseases, ventilator-induced lung injury and neonatal infectious lung injury, were reviewed.　Trend　TREM-1 plays a key role in the neonatal lung injury. It provided a theoretical basis for clinic therapy.