Objective：To investigate the expression of HtrA1 serine protease in  primary hepatocellular carcinoma(HCC) tissue and its relationship with the tumor pathological characteristics.
Methods：HCC tissues and adjacent liver tissues was obtained from 37 hepatocellular carcinoma patients after hepatectomy. Expression levels of HtrA1 serine protease mRNA  were quantitatively analyzed by real-time PCR.
Results：HtrA1 mRNA in liver tumors was 1.2729±0.9911,and HtrA1 mRNA in adjacent tissue was  3.8667±2.8099.The HtrA1 mRNA in adjacent liver tissues were higher than those in hepatocellular carcinoma tissues(P=0.000). Multivariate Logistic regression analysis showed that the level of HtrA1 mRNA, tumor metastasis and tumor capsule were the most important significantly independent  factors for HCC venous invasion.
Conclusions：The expression of HtrA1 in HCC could be as an indicator of the prognosis, metastasis and recurrence.