“San-Bai Decoction” (SBD) has been a traditional Chinese medicine compound preparation for replenishing Qi and promoting blood circulation, whitening skin, and removing blemishes since ancient times. However, its chemical composition and antioxidant activity are not clear thus far, which limits the in-depth study on its pharmacodynamic material basis and efficacy. The objective of this study was to establish the fingerprint profile of SBD, assess its antioxidant activity by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, and find the spectrum-effect relationship of SBD by Grey Relation Analysis (GRA) and Partial Least Squares Regression (PLS). In this study, the fingerprint of SBD was established by high performance liquid chromatography (HPLC), and 20 common peaks were found, among which 6 peaks were designated. The similarities between the fingerprints of 12 batches of SBD and the reference fingerprint (R) were all greater than 0.900. Meanwhile, the antioxidant activities of all batches were concentration-dependent in their linear regression equation. The result of GRA showed that the correlation order of 20 common peaks for DPPH radical scavenging was X13 > X7 > X3 > X6 > X10 > X11 > X4 > X12 > X2 > X18 > X9 > X5 > X19 > X1 > X20 > X16 > X17 > X15 > X8 > X14. At the same time, PLS study demonstrated that the contribution of six identified characteristic peaks to DPPH radical scavenging ability was X1 = X7 > X6 > X19 > X20 > X16. In this study, the spectrum-effect relationship of SBD between its HPLC fingerprint and the antioxidant activity can be used to screen the pharmacodynamic substance basis of its antioxidant action and lay the foundation for establishing quality standards and product development.

“三白汤”（SBD）自古以来就是一种补气活血、美白祛斑的中药复方。但迄今为止，其化学成分和抗氧化活性尚不明确，限制了对其药效物质基础和功效的深入研究。本研究的目的是建立SBD的指纹图谱，通过测量2,2-diphenyl-1-picrylhydrazyl (DPPH)自由基清除能力评估其抗氧化活性，并通过灰色关联分析找到SBD的谱效关系。 GRA) 和偏最小二乘回归 (PLS)。本研究采用高效液相色谱法(HPLC)建立SBD指纹图谱，共发现20个共同峰，其中6个峰被指定。12批SBD指纹与参考指纹(R)的相似度均大于0.900。同时，所有批次的抗氧化活性在其线性回归方程中均呈浓度依赖性。GRA结果显示，DPPH自由基清除的20个常见峰的相关顺序为：X13 > X7 > X3 > X6 > X10 > X11 > X4 > X12 > X2 > X18 > X9 > X5 > X19 > X1 > X20 > X16 > X17 > X15 > X8 > X14。同时，PLS研究表明，6个特征峰对DPPH自由基清除能力的贡献为X1 = X7 > X6 > X19 > X20 > X16。在这项研究中，