Carp were fed with medicated diet added with Chinese nutgall at the weight rate of 0.5% or 1.0% , by examining the indices of liver and blood , the effect of Chinese nutgall to carp bacterial septicemia was studied . The results showed that at the 16 days of medicated diet before infection , the hepatic ACP and AKP activity of prevention and cure group were significantly higher than blank group（P<0.05）；at the 14 days of medicated diet after infection , the blood CRE, UA, UN, ALT and AKP of cure group and prevention and cure group decreased to the normal levels or approach to them （P>0.05） from the significantly pathologic higher levels of 8 days（P<0.05）; the mortalities of prevention and cure groups and cure groups had very significant decrease compared to control group （P<0.01）, prevention and cure groups were very significantly lower than cure groups （P<0.05）, and there was no significant difference between medicated diet of 0.5% and 1.0% （P> 0.05）. Furthermore, Chinese nutgall can improve the non-specific immunity ability of carp , and have a significant effect of preventing and curing the fish bacterial septicemia.
