热疗中热场（比吸收率和温度）分布图象是检验其装置优劣和能否获得较好疗效的主要依据。本文首次采用准稳电场模型和有限单元数值计算方法，对电容射频（13．56MHz)热疗装置在均匀肌肉组织中的比吸收率和温度分布进行模拟计算，得到了在不同极板尺寸及功率及分配条件下的热场分布图象。计算结果表明，两极板电容射频热疗主要靠电极大小来调整热场分布，其有效治疗热区多靠近小尺寸电极一侧，三极极调相式电容射频热疗则主要通过改变三个极板电压的相位，幅值和功率分配方式来调整热场分布形态，有更好的治疗热区调整能力，该研究对电容射频热疗临床选用电极尺寸和功率分配及了解相应的热区形态有指导意义。

in the present paper, a quasi-stationary-state electric field model is used to establish a group of finite-element analysis functions for the radio-frequency capacitive hyperthermic system. The 2DSAR and temperature distribution patterns in the muscle tissue are calculated by using a variety of electrode diameters of two electrodes and under different phase and power relations of three electrodes. Different simulated results are obtained. The simulated results show that,the main heating field of two electrodes RF capacitive hyperthermic system is always near the smaller electrode, and the effective heating region of three electrodes RF capacitive hyperthermic system is controlable by adjusting the phase and power of three electrodes. These results are helpful for the clinical applications.