PURPOSE: To analize the correlation between dynamic vascular pattern and structural histologic type of HCC. MATERIALS AND METHODS: The materials consisted of 35 cases of HCC, which could be classified by structural histologic type and had available preoperative arterial dominant images. Excluding one case of pseudoglandular type, we compared structural histologic type of the tumors(trabecular group;13 cases, mixed group;10 cases, and nontrabecular group ;11 cases) with dynamic vascular pattern such as degrees of tumor staining, severity of tumor vessels on hepatic angiography, and with enhancing degrees of early phase relative to late phase on two-phase incremental bolus dynamic CT. RESULTS: In hepatic anglogram, trabecular group showed stronger tumor staining and more prominant dilatation and irregularity of tumor vessels than those of nontrabecular group, and In two-phase incremental bolus dynamic CT, and trabecular group showed more prominant tumor enhancement in early phase than those in late phase. CONCLUSION: The trabecular type(typical) and non-ti'abecular type of HCC showed radiologically different vascular patterns and therefore we believe that this maybe the basis with which diagnosis and treatment policy of radiologically atypical HCC could be made.