Abstract: Objective:To evaluate the safety and efficacy of the hollow fiber bioartificial liver system in canines with acute liver failure.Methods:9 canines with acute liver failure by Acetaminaphen received TECA-I bioartificaial liver system （BALS）from Hong kong TECA Limited, blood was perfused through a hollow fiber tube containing （1~3）×10¹⁰ the porcine hepatocytes. 10 canines with acute liver failure by Acetaminaphen received drugs. Each treatment lasted 6 hours. Results:BALS treatment resulted in beneficial effects with decreased plasma ammonia （from 135.9±17.5 to 65.7±22, 32.5±8.8 umol/L）, GPT（from 97.8±8.7 to 64.8±11.9,19.0±6.3 U/L）, GOT （from 103.0±16.7 to 75.7±19.6,26.5±5.0 U/L） and AKP （from 158.3±12.1 to 114.5±19.8,43.8±5.6 U/L） which lasted for the duration of the treatment and 30 days thereafter. In contrast, 10 canines with acute liver failure in the drug group wre death after treatment 1~2 days. Conclusion:This bioartificaial liver system is safe and efficacious in canines with acute liver failure.