The authors have developed the integrated system of the non-invasive ultrasound diagnosis and treatment in order to decrease the suffering of patients. The concept of the proposed system is to destroy tumors or stones in the body utilizing the High Intensity Focused Ultrasound (HIFU) directly without injuring the healthy tissue of the patient. During the treatment, the system tracks and follows the affected part which moves owing to respiration, etc. In this paper, the servoing performance of the system is discussed and investigated at first. Secondly, the authors propose a feed-forward controller. It utilizes the periodical motion of the affected part by the respiration to enhance the servoing performance. Finally, the experimental results are reported to confirm the effectiveness of the proposed feed-forward controller.