Identification of hepatocellular carcinoma- associated tumor antigens is necessary and pivotal for specific immunotherapy in hepatocellular carcinoma (HCC) patients. In the present study, HCC cDNAs are constructed into ZAP cDNA expression library and screened by sera of patients with HCC. The positive clones are DNA sequenced and analyzed by bioinformatics. Thirty-one genes of hepatocellular carcinoma-associated tumor antigens are identified, of which 1 is unknown and 30 are known. The proteins encoded by these known genes can be classified into 8 categories: constitutive molecules of hepatocytes, RNA transcription and splicing-associated molecules, protein metabolism-associated molecules, energy synthesis-associated molecules, signal transduction molecules, cell adhesion molecules, immunosuppressive molecules, and proteins with unknown function. Among these genes, CAGE is a cancer-testis (CT) antigen. It is concluded that identification of hepatocellular carcinoma-associated tumor antigens provides potential targets for immunotherapy of HCC patients and facilitates explanation of carcinogenesis of HCC.