Abstract:To observe the pathological changes of liver from rat following long-term intake of sausage with different content of N-nitrosodimethylamine （NDMA）.Rat liver damage model was established by drinking water containing 30 μg/kg NDMA water.When the serial progression of this model was divided into the inflammation stage，the fibrosis stage，the cirrhosis stage，and hepatocellular carcinoma stage，the rats from feeding control diet group and sausage diet groups were executed.Serum total protein （TP），albumin（ALB），aspartate aminotransferase（AST），alanine aminotransferase（ALT）and alkaline phosphatase（ALP）were detected.The liver index was calculated and the liver tissues were observed for pathological examination.Results showed that the pathological changes of typical hepatitis，liver fibrosis，cirrhosis and liver cancer occurred in the liver of NDMA model rats at the 7th，17th，25th and the 33th week，respectively.The general condition of rats in three sausage diet groups at different time points did not show any significant changes compared with control group，as did the change of liver index.But there are some changes in the level of serum TP，ALB，AST，ALT and ALP.The pathological changes of liver were gradually aggravated from 18%control sausage diet group （S1 group），containing 18%NDMA exceeded the limit sausage diet group （S2 group）to containing 36%NDMA exceeded the limit sausage diet group（S3 group）during the whole experimental period（33w）.The hepatitis score in each group continuously increased from S1 group，S2 group，S3 group to NDMA group，and increased with the extension of experimental time.The long－term intake of sausage with NDMA exceeded limit led to rat liver damage，and the extent of damage was related to the content of NDMA of sausage and the feeding time in sausage diet.