The in vivo conductivity of the liver tissue measured at 460kHz was 3.27±0.28S/m. Current and temperature distributions were calculated using the finite element method (FEM) and the measured conductivity in order to show better configurations of the electrodes used in radiofrequency ablation. Two FEM models were made for straight electrodes, and another two FEM models for hook electrodes. When two active straight electrodes were used and the power was put on and off, the total applied energy became less than when a straight electrode and a dispersive electrode were used. The two pairs of four hook electrodes produced the largest volume of ablation, but they might cause a problem because of their size when they were inserted into the liver.