The fingerprint technique has been studied frequently as a useful strategy for quality of traditional Chinese medicine. A novel potency fingerprint that can quantitatively analyze the antioxidant activity of individual constituent and provide the total antioxidant activities of the samples has been developed by high-performance liquid chromatography coupled with ultraviolet and pyrogallol-luminol chemiluminescence detection (HPLC-diode array detection (DAD)-PLD). Hierarchical clustering analysis has been used as a powerful pattern recognition tool to identify and classify Danshen injection from different factories. In addition, the combination use of the chromatographic fingerprint and potency fingerprint with principal component analysis was applied to quality control of Danshen injection. The results demonstrated that the proposed potency fingerprint was a useful means to control the quality and to clarify the possible mechanism of action of herbal products.