Objective: To investigate the effect of different root diameters and section thicknesses on drying efficiency and active components content in Salviae Miltiorrhizae Radix et Rhizoma. Method: HPLC was used to measure the content of active components in Salviae Miltiorrhizae Radix et Rhizoma under different drying conditions.The chromatographic conditions of liposoluble components was mobile phase of acetonitrile-0.2% acetic acid and detection wavelength of 270 nm.The chromatographic conditions of water-soluble components was mobile phase of acetonitrile-0.2% formic acid and detection wavelength of 286 nm. Result: The thinner of Salviae Miltiorrhizae Radix et Rhizoma section

the faster of drying process for the same diameter of roots.The content of rosmarinic acid was the highest as the root diameter was 0.3-0.4 cm and the section thickness was 0.2-0.3 cm.The content of salvianolic acid B was the highest as the root diameter was 0.4-0.5 cm and the section thickness was 0.2-0.3 cm.The content of dihydrotanshinone was the highest as the root diameter was 0.4-0.5 cm and the section thickness was 0.1-0.2 cm.The content of cryptotanshinone was the highest as the root diameter was 0.3-0.4 cm and the section thickness was 0.1-0.2 cm.The content of tanshinone Ⅰ and tanshinone ⅡA were the highest as the root diameter was 0.4-0.5 cm and the section thickness was 0.2-0.3 cm. Conclusion: When the root diameter is 0.4-0.5 cm and the section thickness is 0.2-0.3 cm

it can ensure the quality of Salviae Miltiorrhizae Radix et Rhizoma sections to the maximum extent

this study provides a theoretical basis for optimization of its production and drying technology.