As a novel cell cultivation method, cell cultivation using a liquid/liquid interface system (culture medium/fluorocarbon) has been investigated. Cell adhesion at the interface appears to be dependent on the contaminants contained in the fluorocarbon. Tn this study, the effect of surfactant on the growth and adhesion of the cells was studied. Although the cells could not anchor at the interface between nonionic surfactant-added medium and fluorocarbon, cell growth was observed when ionic surfactant, instead of nonionic surfactant, was used. When ionic surfactant was added to fluorocarbon, cell growth was better than that at the interface between ionic surfactant-added medium and fluorocarbon. In particular, the cell growth at the interface using fluorocarbon added pentafluorobenzyl chloride or perfluorooctanoyl chloride was similar to that at the polystyrene surface, which indicates that it is important to add the surfactant to fluorocarbon.