Abstract: OBJECTIVE To compare the antioxidant activities of different polar extracts of Hibisci Mutabilis Folium,to determine the antioxidant activity of ethyl acetate extract and to establish HPLC fingerprint in order to study the spectrum effect relationship.METHODS The antioxidant activity was evaluated by DPPH method and ABTS method to screen the best extracts of Hibisci Mutabilis Folium,determine the antioxidant activity of the best extract of 13 batches of Hibisci Mutabilis Folium from different habitats,and establish HPLC fingerprint,for similarity analysis,cluster heat map analysis and principal component analysis (PCA),and the spectral effect relationship was analyzed by partial least squares regression (PLSR).RESULTS The antioxidant activity of different polar extracts of Hibisci Mutabilis Folium was ethyl acetate extract>n-butanol extract>water extract>petroleum ether extract.There were 17 common peaks in the ethyl acetate extract of 13 batches of Hibisci Mutabilis Folium,including 5 components.Peak 4 was fraxetin,peak 6 was rutin,peak 8 was isoquercetin,peak 10 was kaempferol-3-O-rutoside and peak 15 was tilioside,13 samples with a similarity of 0.912-0.995.Cluster heat map analysis and PCA grouped 13 batches of Hibisci Mutabilis Folium samples into two categories;PLSR analysis showed that the regression coefficients of peak 3,peak 4(aesculin),peak 6(rutin),peak 10(kaempferol-3-O-rutoside) and peak 12 were positively correlated with antioxidant activity,and the contribution was large (VIP>1),which was the main effective component of antioxidant activity.CONCLUSION The ethyl acetate extract of Hibisci Mutabilis Folium has good antioxidant activity.The antioxidant activity of Hibisci Mutabilis Folium is the result of the synergistic action of multiple components,which reveals the pharmacodynamic material basis of the antioxidant activity of Hibisci Mutabilis Folium.