Abstract: We investigated the total solid and the active component yields from fresh Eucommia bark by singlefactor experiments of aqueous extraction under the liquid ratio of 1∶20 to 1∶60 g·mL^-1, extraction time from 10-120 min, and extraction temperature from 30℃ to 90℃. Under the optimum extraction processes of singlefactor experiment, the total solid yield was 11.61%, and the extraction yields of chlorogenic acid, aucubin, geniposide and pinoresinol diglucoside were 0.073%, 0.704%, 0.122% and 0.108%, respectively. Aqueous extraction has advantages of simple process without environmental pollution and solvent recovery.

Key words: Eucommia, water-bath, total solid, active component