PURPOSE: To evaluate the color Doppler imaging patterns of hepatoma, hemangioma, and metastasis. MATERIALS AND METHODS: The study comprised 37 patients with liver mass lesions: 12 patients had hepatoma, 15 had hemangiomas and10 had metastatic liver cancers. All 37, who showed hepatic mass on gray scale ultrasonogrphy, were analyzed prospectively. Color mapping of tumors was performed for these patients, and the fastest or next fastest vessel was spectrally analysed to show blood pattern and to measure peak velocity. RESULTS: In all the 12 patients with hepatoma, spectral analysis revealed exteusive pulsating arterial blood flow within the tumor ; peak velocities were 7~65cm/sec(mean 34cm/sec). In ten hemangiomas(66%) color mapping revealed blood flow within the tumor and spectral analysis revealed this possibility in eight of the ten tumors. In none of these patients was a pulsating continous wave observed ; peak velocity was 5~21cm/sec(mean 12.8cm/sec). In no mestastatic tumors was blood flow observed. CONCLUSION: Color Doppler imaging is helpful in the differentiation of hepatoma, hemangioma, and metastatic tumor in the liver.