Image-guided radiofrequency ablation (RFA) is one of the most popular and widely applied local tissue ablation modality. It has many advantages like easy operation, minimally invasive, safe and efficiency. The success of RFA treatment strongly depends on the completeness of tumor destruction with minimum amount of affected native tissue, while damages on surrounding organs or large blood vessels have to be avoided. Therefore, the treatment effect is closely related to the ablation accuracy. To get the best clinical effect, it requires scientific preoperative analysis, accurate treatment planning and precise surgical operation. This talk focuses on hepatic RFA planning as well as the solution of thermal field induced by RFA. In particular, we propose a new method named by “Homogenized perturbation theory” to solve the thermal field induced by RFA.