Objectives: To assess the efficacy and safety of acellular dermix matrix for the prevention of gustatory sweating syndrome after parotidectomy.Methods: Medline,CENTRAL,EMBASE,OPEN SIGLE,CBM,VIP,CNK and Wanfang database were searched electronically on March 17th 2013.Hand-searching covering 19 relevant Chinese journals were also performed.Risk of bias assessment,which was suggested by Cochrane handbook for systematic reviewers of intervention review,and data extraction of included studies were delivered by two reviewers in duplicate.Meta-analysis was done with Revman5.2 and STATA 11,and the quality of evidence was evaluated by GRADE.