Abstract: To study the hotair drying characteristics,drying kinetics mathematical models and the effect of different drying condition on the effective constituent,which included salvianolic acid B and tanshinoneⅡA of Salvia miltiorrhiza Bunge.Methods:The experiment was carried out at different hotair drying temperatures (50,60,70 and 80 ℃) and at different diameters (1.12,0.84 and 0.46 cm).The drying characteristics were detected and the drying kinetics mathematical model was established.Meanwhile,salvianolic acid B and tanshinoneⅡA were detected by highperformance liquid chromatography (HPLC).Results:The drying process occurred in falling rate periods;According to statistical parameters,the Page model predicts and describes the drying process more accurately than others.There was a good agreement between the experimental and predicted values of Salvia miltiorrhiza Bunge;The Fick’s second law of diffusion was employed to calculate the value of moisture effective diffusivity (Deff),which ranged from 5.08389 × 1010 ～2.54195 × 109m2/s,and increased with the increasing of drying temperature;The activation energy determined from Arrhenius equation was 49.0967 kJ/mol;The content of salvianolic acid B and tanshinoneⅡA is higher when the temperature rang 50 to70 ℃.Conclusion:The drying process of Salvia miltiorrhiza Bunge only contained deceleration stage.The Page model was the best suitable for predicting moisture ratio.The research results of Salvia miltiorrhiza Bunge has a certain guiding significance to practical production.

Key words: Salvia miltiorrhiza Bunge, hotair drying , kinetic modeling