Objective: To find out nanofiltration enrichment process of extract solution of Salviae Miltiorrhizae Radix et Rhizoma. Method: Taking salvianolic acid B as detection object

HPLC was employed to determine retention rate of salvianolic acid B with mobile phase of acetonitrile(A)-1% acetic acid(B) for gradient elution(0-20 min

5%-15%A;20-50 min

15%-40%A) and detection wavelength at 281 nm.With retention rate and membrane flux of salvianolic acid B as indexes

effects of operating pressure

adsorption characteristics and other factors on concentration process were investigated by single factor tests. Result: Retention rate of salvianolic acid B increased with decreasing of aperture and unchanged with change of pressure and cycles of concentratin.Membrane flux was positively correlated with intercept relative molecular weight and pressure

decreased as concentration ratio increased.Retention rate of salvianolic acid B was 99.5% when nanofiltration membranes aperture was 300 Da

membrane flux was 12 L·m-2·h-1

this process had no obvious influence to other ingredients in Salviae Miltiorrhizae Radix et Rhizoma with high concentration efficiency. Conclusion: Nanofiltration concentration is useful for concentrating liquid including thermal instability class ingredients

it has high efficiency and low losses of active ingredients.