Abstract: Based on the previous study, chlorogenic acid was isolated and purified from leaves of Eucommia ulmoides Oliver in an pilot scale experiment by the following process:refluxing by 40% ethanol(80℃, 2 h, ratio of material to solvent:1:16, extract twice)^→extracts preparation(vaccum evaperation, drying at 80℃)^→extraction by water(4 times)^→precipitation by Pb(OAc) 2\^→resolution of chlorogenic acid by 20% sulfuric acid^→extraction by ethyl acetate(20 times)^→condensation^→re crystallization.The yield of chlorogenic acid is 0.53%, at purity 98.35%.Results of the experiment showed that this technological process was feasible and practical.It was found that no isomers of chlorogenic acid occurs in the leaves of E.ulmoides after comparing with honeysuckle flowers and raw coffee beans, in which the occurrence of iso-chlorogenic acids was reported.This is traceable to the views of secondary metabolism and chemical reaction.

Key words: chlorogenic acid, leaves of Eucommia ulmoides Oliver