Objective: To establish a purification process for W2 [3-O-α-L-Rha-(1→6)-β-D-Glu-(1→4)-β-D-Glu-(1→4)-β-D-Rib-(1→3)-α-L-Rha-(1→2)-α-L-Ara oleanolic saponin]in Clematis manshurica by macroporous resin. Method: The content of W2 was determined by HPLC

and it was used as index.Type of macroporous adsorption resin was screened by inspecting the adsorption and desorption ability of nine candidate macroporous resins.The static adsorption kinetics and dynamic gradient elution of the best type of macroporous resin was investigated

single factor tests were adopted to optimize purification process. Result: Optimum purification process was as following:the concentration of sample solution of 0.4 g·mL-1

adsorbed by LX-17 macroporous resin column with a flow rate of 1.5 BV·h-1

washed by 4 BV of water and 5 BV of 40%ethanol for removing impurity with a flow rate of 3 BV·h-1

taking 1 BV of 80%ethanol to remove the solution in column

and eluted by 6 BV of 80%ethanol for enrichment of W2 with a flow rate of 1.5 BV·h-1.Under these conditions

the purity of W2 in dry extract was 43.14%. Conclusion: LX-17 macroporous resin is suitable for separation and purification of W2.This optimized process is reasonable

stable and feasible

which can obtain W2 sample with high purity.