To investigate whether Polygonum cuspidatum (PCE) has remedy effects on injured fish liver，primary hepatocytes were isolated from Jian carp and randomly divided into six groups: group I (blank control), group II (treated with CCl4), group III (treated with 800 μg/mL PCE), IV (treated with 200, 400 or 800 μg/mL PCE before CCl4 treatment), group V(treated with 200, 400 or 800 μg/mL PCE after CCl4 treatment), group VI(treated with 200, 400 or 800 μg/mL PCE before and after CCl4 treatment), 12 h after treatment, culture medium of hepatocytes were collected to determinate the activity of alanine aminotransferase (GPT), aspartate aminotransferase (GOT), lactic acid dehydrogenase(LDH), superoxide dismutase (SOD), the content of malondialdehyde (MDA) and the cell viability of hepatocytes in each group. The results showed that in group III，GOT, GPT, LDH, SOD, MDA and cell viability had no obvious change compared with the group I (P＞0.05)，indicating 800 μg/mL PCE had no cell toxicity and can be used for further testing. In group IV, the remedy effect of 800 μg/mL PCE was better than the other two concentrations, which very significantly decreased the activity of GOT in culture medium (P<0.01); significantly decreased the activity of GPT and LDH (P<0.05); and significantly increased the cell livability of hepatocytes (P<0.05), compared with the group II, but the difference in the content of MDA and the activity of SOD were not statistically significant (P＞0.05). In group V, the effect of 800μg/mL PCE was better than the other concentrations, which could very significantly decrease the activity of GOT in culture medium (P<0.01); significantly decrease the activity of LDH (P<0.05); significantly increase the cell viability (P<0.05), compared with the group II, but the difference in the content of MDA and the activity of GPT were not statistically significant (P＞0.05). In group VI, the effect of 800 μg/mL PCE was better than the other concentrations, which very significantly decreased the release of GOT, GPT, LDH in hepatocytes (P<0.05)；significatntly decreased the content of MDA (P<0.05); significantly increased the cell viability of hepatocytes (P<0.05), compared with the group II. It is concluded that 800 μg/ml PCE in group VI had the best effect, which could effectively protect the primary hepatocytes against CCl4 induced injury, which was possibly associated to its anti-oxidative activity.