Objective: To prepare Danshen Injection (Radix Salviae Miltiorrhizae) by micelle-ultrafiltration. Methods: For preparing Danshen Injection, we packed the impurities in the macrofiltered liquor of Radix Salviae Miltiorrhizae with micelle of Tween-80, and ultrafiltered the compounds with ultrafiltration membrane withholding molecular weight more than 50000. Then we evaluated the process with the comprehensive indexes including loss rate of UV absorbance, loss rate of Protocatechualdehyde and the stability of transparence. Conclusion: The process of Danshen Injection prepared by micelle-ultrafiltration is better than that of ordinary ultrafiltration.