Abstract: Neutrophil extracellular traps (NETs) are neutrophil-derived DNA structures. They have been shown to trap and kill microorganisms, playing a critical role in host defense. Increasing evidence has shown that NETs have a close relationship with tumor progression. And their contribution to tumor recurrence and metastasis has been demonstrated in a number of studies.Furthermore, the clinical significance of NETs has also been highlighted. In this review, emphasis was laid on the mechanism of the formation of NETs and their role in tumor progression in a cancer promoting microenvironment. In addition, the clinical value of NETs was also explored.