In order to analyze the correlation between metabolites and antioxidant activity,the physical and chemical indexes and active substances (pH,total acid,total sugar,total phenols,total flavone and organic acids),and antioxidant capacity (scavenging capacity against DPPH radical,hydroxyl radical,superoxide radical and reducing power) were investigated during natural fermentation process of fig.In order to determine the optimal natural fermentation time of fig enzyme,the correlation between metabolites and antioxidant activity and the comprehensive evaluation index (CEI) were performed by principal component analysis method.The results showed that pH decreased continuously,the total flavone irregularly fluctuated,and the total acid,total phenol,DPPH radical,hydroxyl radical,superoxide radical scavenging ability and reducing power initially increased and then decreased.Thirteen major organic acids were detected in fig enzyme,in which lactic acid,succinic acid,malic acid,citric acid,glucuronic acid and pantothenic acid were more abundant.The comprehensive evaluation value (CEI) was highest at 60 d and then continued to decrease after 80 d,which could be as the end point of pre-fermentation of fig enzyme and provided a theoretical basis for the precise fermentation of fig enzyme.