Objective:To search the marker of micrometastatic hepatocellular carcinoma (HCC).Methods:Peripheral blood samples were obtained from 65 patients with hepatocellular carcinoma,21 non  HCC malignant tumors,22 chronic hepatitis B or cirrhosis,and 21 normal healthy volunteers.To identify hepatocellular carcinoma cells in peripheral blood, liver  specific alpha  fetoprotein(AFP)mRNA was amplified from total RNA extracted from whole blood by nested reverse transcription  polymerase chain reaction (Nested  RT  PCR).Results:AFP  mRNA was not detected in the normal healthy volunteers and patients with non  HCC malignant tumors.The presence of AFP  mRNA in patients with HCC(44/65,67.7%)was higher than those with chronic hepatitis B or cirrhosis(2/22,9.1%,  P