Objective:To explore the correlation between high performance liquid chromatography (HPLC)fingerprint and free radical-scavenging activity of Rhamnus heterophylla leaves. Method:Fingerprint of eight batches of R. heterophylla leaves from different regions and harvest times was established by HPLC. Origin Pro 2017 software was used for hierarchical cluster analysis(HCA) and principal component analysis (PCA) to evaluate the common peaks in the fingerprint on the basis of traditional similarity evaluation method. The free radical-scavenging activity was determined by 1

1-diphenyl-2-picrylhydrazyl radical 2

2-diphenyl-1-(2

4

6-trinitrophenyl)hydrazyl (DPPH) assay. Partial least squares regression (PLSR) and grey relational analysis (GRA) were used to study the relationship between HPLC fingerprint and free radical-scavenging activity. Result:The HPLC fingerprint of eight batches of R. heterophylla leaves was established

and 11 common peaks were determined

with the similarity of 0.948-0.976.Six peaks among common peaks were identified by comparing to reference substances:x1

x2

x5

x8

x10

x11 referred to protocatechic acid

luteoloside

quercetin

kaempferol

emodin-8-O-α-L-rhamnoside

and emodin

respectively. The samples were clustered into four categories. All of the samples had different degrees of scavenging free radical activity. The result of GRA showed that the order of correlation was x11 > x10 > x8 > x1 > x9 > x4 > x3 > x2 > x6 > x5 > x7.The regression equation established by PLSR analysis was Y=99.769 17-0.357 49x1-0.001 36x2-0.002 65x3+0.059 63x4+0.011 81x6+0.010 63x7-0.006 99x8-0.009 14x9+0.054 27x10+0.022 75x11. Conclusion:The free radical-scavenging activity of R. heterophylla leaves was the result of the combined effects of multiple components.