Glypican-3 (GPC3) is a promising tumor marker for hepatocellular carcinoma (HCC) diagnosis with high sensitivity and specificity. The aim of this study was to establish an immunohistochemical detection method for GPC3 using the 7D11 monoclonal antibody (7D11 mAb) and evaluate its application for HCC diagnosis. The feasibility of the 7D11 mAb was evaluated by immunohistochemistry performed on adjacent normal liver and intrahepatic cholangiocarcinoma (ICC) samples, Furthermore, the serum GPC3 levels were evaluated in 40 HCC patients, 7 ICC patients and 50 healthy donors. The results showed that GPC3 was expressed in 85% of HCC tissues (34/40), but was undetectable in ICC tissues and adjacent normal tissues.GPC3 was significantly increased in the serum of HCC patients (17/40, 42.5%) but was undetectable in the serum of ICC patients (0/7, 0%) and healthy donors(0/50, 0%). This prospective study evaluated the clinical usefulness of 7D11 mAb for GPC3 detection in HCC patients. In conclusion, the use of 7D11 mAb might be good for GPC3 large-scale applications for clinical diagnosis of HCC.