Abstract: Preservation of hepatocytes is a key technical factor toward the successful clinical application of hybrid artificial livers. It was possible to culture hepatocytes that had been preserved with collagen gel for 8 and 14 days in 4°C University of Wisconsin solution. Phase-difference and scanning electron microscopy showed that most of the stored hepatocytes maintained a round-shaped morphology. In the 14 day preservation group, on Days 2 and 8, respectively, ureogenesis was 98.3% and 69.6%, gluconeo-genesis was 65.2% and 80.7%, lidocaine clearance was 81.7% and 72.5%, urea synthesis after ammonia load was 47.6% and 57.5% of those in the comparable control group. This implies that preserved hepatocytes maintained adequate functional capability even after 14 days of preservation. We suggest that our preservation method will be valuable for the future application and development of a practical hybrid artificial liver.