The paper describes a procedure for the initiation, subculture and continued proliferation of adventitious roots of Panax ginseng and Panax quinquefolium, which resemble hairy roots. The technique took advantage of the high powerful activity of a new synthetic auxin: benzo[b]selenienyl acetic acid (BSAA). Such initiation from root explants was dependent upon the season, the type and concentration of auxin. The hairy-like roots of ginseng could be subcultured by transfer every 4 weeks to fresh liquid medium either in agitated Erlenmeyer flasks or in bioreactors. Optimal conditions for a continued multiplication (up to 14 per month) were determined. The only practical problem was the limitation of the fresh mass as inoculum: the multiplication rate decreased with the increased quantity of roots. It is postulated that a root growth inhibiting substance was released into the media by the proliferating ginseng hairy roots.