Protoplasts of Panax ginseng C. A. Meyer and Aralia continentalis K. (Araliaceae) were isolated from callus cells and mesophyll cells, respectively. The maximum yield of protoplasts isolated from callus cells of P. ginseng were obtained by incubation for 3 hrs in the enzyme mixture of 0.5% macerozyme, 1.5% cellulase, and 0.5 M mannitol as an osmoticum. In the case of mesophyll cells of A. continentalis, the highest yield of protoplasts were obtained by incubation for 5 hrs in the enzyme mixture of 1% macerozyme, 2% cellulase, and 0.6 M mannitol. A polyethylene glycol (PEG) treatment induced an intergeneric fusion of the protoplasts. The fusion products, that is, heterokaryocytes were obtained by treatment of 50% PEG containing 0.05 M Ca salts.