An HPLC-photodiode array detector (PDAD) method was developed for simultaneous determination of danshensu, salvianolic acid B, and paeonol in a traditional Chinese medicinal preparation ShuangDan oral liquid, which is widely used to treat coronary heart disease in China. The samples were separated on a SinoChrom ODS-BP C18 column with the column temperature maintained at 30 degrees C. The mobile phase was composed of methanol and 2% (v/v) glacial acetic acid at a flow rate of 1.0 mL/min. The separation was finished within 30 min using linear gradient elution. All calibration curves showed good linearity (r > 0.9997) within the test ranges. The method was simple, reliable, accurate, and specific. The intraday and interday precisions (RSD) were less than 0.85%. The recoveries were between 96.97 and 102.14%. The method was successfully applied to the determination of the three components in three commercial samples of ShuangDan oral liquid. The results indicated that the developed HPLC-PDAD assay could be readily utilized as a comprehensive quality control method for ShuangDan oral liquid.