 A robotic system has been developed that includes a needle-path planning system and a needle-guiding robot arm with computed tomography CT guidance. The robot consists of robot base, 5-axis robot arm with guiding end-effector and path-planner. Optical tracking system with a custom-designed registration jig is used for the spatial registration and validation. Advantages of the robotic system would be accurate targeting with diverse angulation of the robot arm in CT-guided tumor ablation. Furthermore, robotic intervention might potentially decrease procedure time and radiation exposure to patients. The purpose of this clinical trial with patients with hepatocelluar carcinoma is to assess the safety and efficacy of our CT-guided needle-guiding robot. 