Recently therapeutic trail of unresectable hepatocellular carcinoma with radioiodinated fatty acid esters in on going study as one of the promising treatment modality. The Purpose of study is to calculate the tumor as well as the tumor edge doses by means of external count methods using 1-131-Lipiodol paraffin phatoms. The radioactivity of each tumor phantoms ranging from 2-5cm in diameter were measured with TLD and lon chamber methods and compare to external count method of Gamma camera computer system. the tumor dosimetry in patients with intrahepatic 1-131-Lipiodol in fusion cam be calculated from those baseline studies of phantoms. Results as follows: 2. The tumor edge dose will be delivered about 10% of total tumoral doses and decreased lower following inverse square law. 3. The radioactivity counts(CPM) of tumor phantoms related to the tumor diameter and depth can be applied to dose calculations in the human subjects after consideration of transmission factor.