The receptor of urokinase-type plasminogen activator (uPAR) on hepatocellular carcinoma (HCC) cells were investigated immunohistochemically. Staining of serial sections with antibodies against CD68 (a marker for macrophage) and uPAR revealed that the cells positive for uPAR were mostly macrophages and a few neutrophils. HCC cells were negative for uPAR in all cases except one, in which the cells were poorly differentiated and underwent sarcomatous change. The labeling index (positive cell number/mm 2 ) of uPAR was significantly higher in HCCs showing invasive growth (68 ± 59, n=5) than in those showing expansive growth (12.8 ± 9.6, n=7) (p<0.05). It was especially high in the lesion where HCC cells were infiltrating in the neighboring tissue and also in the metastatic lesion of lymph nodes. HCC showing invasive growth may produce substances which activate uPAR expression on macrophage in and around HCC, and the expression of uPAR may participate in lymph node metastasis of HCC.