Soluble interleukin-2 recepter(sIL-2R）levels, NK activity and T lymphocyte subpopulation in peripheral blood were determined in 34 cases of primary liver cancer (PLC). The results showed that the mean level of sIL-2R and CD8 in the patients with primary liver cancer were higher than that in health subjects (Plt;0.01or Plt;0.05), NK activity and T lymphocyte subpopulation (CD3,CD4,CD4/CD8) in the patients with primary liver cancer were much lower than that in health subjects (Plt;0.01), sIL-2R levels in stage II, III patients with primary liver cancer were significantly higher than that in stage I (Plt;0.01). The 6-month mortality rate in 3 groups of patients with sIL-2R level ≥1000u/ml, 500-1000u/ml, andlt;500u/ml were 80.0%, 29.4%and 0 respectively. sIL-2R levels were also decreased (Plt;0.05) in patient with primary liver cancer 4 weeks after immune therapy, but the cell-mediated immunity was increased. It suggests that sIL-2R level determination in peripheral blood is a new biological marker for the assessment of the stage, the response to medical intervention, the prognosis and cell-mediated immunity in primary liver cancer.