Abstract: Objective: To establish a quantitative analysis of multi-components by single-marker (QAMS) method for simultaneous determination of isoorientin, orientin and aspalathin in Aspalathus linearis and its products. Methods: HPLC was used with acetonitrile-acetic acid aqueous solution as mobile phase, gradient elution and isoorientin as reference substance to establish its relative correction factors with orientin and aspalathin, and the method was verified. QAMS method and external standard method were used to calculate the contents of three components in Aspalathus linearis and its products. The differences of the results obtained by the two methods were compared to verify the accuracy and feasibility of QAMS method. Results: The linear relationship of the three components was good within a certain linear range, R²>0.999, the repeatability RSD value was less than 3%, and the recovery was in the range of 97.4%~101.8%. The method had good repeatability and good durability under different experimental conditions (RSD<3%). There was no significant difference between the content measured by external standard method and that calculated by QAMS method (P>0.05). Conclusion: The QAMS method for simultaneously measuring the content of three components was accurate and reliable to evaluate the quality of Aspalathus linearis and its products.