Monkey kidney cells (Vero), human embryonic kidney cells (293), human liver cells (PLC/PRF/5), and primary rat, dog, and porcine hepatocytes formed spherical multicellular aggregates (spheroids) in the pores of polyurethane foam which was used as a cell culture substratum. These spheroids of various cell types express high cell activity for a long period. A practical hybrid artificial live support system composed of a multi-capillary polyurethane foam packed-bed type cell culture module including primary hepatocyte spheroids was developed. The success of the system is indicated by an 80% recovery rate in hepatic failure rats which died in control experiments.