Abstract: Human β-defensin-2 (HBD-2) is an inducible small cationic antimicrobial peptide.It has been shown that HBD-2 elicits antimicrobial effects on multidrug-resistant pathogens in addition to many normal pathogens.HBD-2 also has certain effects on prognosis of some infectious diseases,furthermore,it is probably to be used as an biomarker in the occurrence and development of the infectious disease.