The methanolic (MeOH) extract of A. fruticosa bark, which showed immune-regulatory activities, was separated to purify an active compared by means of a multi-stage column chromatography. This resulted in the isolation and characterization of an isoflavone glycoside named 4', 6-Dimethoxyisoflavone-7-O-β-D-glucopyranoside. Immuno-regulatory activities of the crude extract of Amorpha fruticosa LINNE bark were compared with that of an isoflavone glycoside (4', 6-dimethoxyisoflavone-7-O-β-D-glucopyranoside). The crude methanolic extract of A. fruticosa and purified single compound showed 16% of relatively low cytotoxicity at a maximum concentration of 1.0 g/L in cultivated normal human lung cell line (HEL299). Cell growth of human T cells was increased up to 15%, 0.5 g/L of the crude extract added group. This was higher than a single compound added one. On the other hand, specific production rates of IL-6 and TNF-α from T cell were higher in the purified compound treat group (0.82×10-4 pg/cell and 1.08×10-4 pg/cell, respectively), compared to 0.5 g/L of the crude extract added group (0.65×10-4 pg/cell and 0.84×10-4 pg/cell, respectively). In addition, the growth of NK-92MI cells incubated with the crude extract was higher up to 56% over the cells grown with a single compound (0.5 g/L). In overall, the crude extract showed relatively higher immuno-regulatory activities compared with a single compound, probably due to the synergic effect given by other substances existed in the crude extract. Even though the siolated compound stimulated higher secretion of cytokines from human T cells.