In order to study the protect effects of polyporus polysaccharide on hepatocytes injured by carbon tetrachloride (CCl4),the primary hepatocytes in Jian carp were isolated by trypsin digestion method,cultured in vitro and induced by CCl4.The hepatocytes were treated with polyporus polysaccharide of different concentrations,the culture medium of hepatocytes were then collected,the content of alanine aminotransferase (GPT),aspartate aminotransferase (GOT),superoxide dismutase (SOD),malondialdehyde (MDA),lactic acid dehydrogenase (LDH),and cell livability of primary cultured hepatocytes were determinated.Total RNA in primary cultured hepatocytes was extracted with trizol reagent and the mRNA levels of CYP3A were determined by RT-PCR.The results showed that in the pre-treatment group at 0.8 mg/mL of polyporus polysaccharide,the release of GOT,GPT,MDA were significantly decreased,the activity of SOD was increased,the release of LDH was decreased,the cell livability and the expression of CYP3A at mRNA level were increased,indicating best protect effect of this group.It can be concluded from the data obtained that polyporus polysaccharides could effectively protect the primary cultured hepatocytes against CCl4induced injury.