Objective: To study on the change of content and intrinsic viscosity from water extract of Gardeniae Fructus by ultrafiltration. Method: Different relatively density was determined by Ubbelohde viscometer. Investigated the change of intrinsic viscosity by dealed with ultrafiltration of different retention molecular weight

then study on the effect of deacetyl-asperulosidic acid methyl ester

genipin-1-β-D -gentiobioside and geniposide by ultrafiltration. Result: With the pore size decreased and relative density increased

the loss rate of components have a tendency to increase;Relative viscosity of extract from Gardeniae Fructus reduced significantly after ultrafiltration

with the membrane pore size and extract the relative density decreased

the relative viscosity of ultrafiltrate also decreased. Conclusion: Viscosity of water extract from Gardeniae Fructus decreased significantly after ultrafiltration.