Minimally invasive surgery and therapy is popularly used both for diagnosis and for surgery. Teleoperation, a promising surgery, is used to protect the surgeon from X-ray radiation as well as to address the problem of lacking experienced surgeons in remote rural areas. However, surgery success ratio should be considered because the surgeon was separated from the patient remotely. A most effective addressing method to improve success ratio is design of a haptic interface as a master console, which can provide the ''immersive'' operation to the surgeon. In this study, a haptic catheter operation system for teleoperation through exploiting magnetorheological fluids is proposed to solve the safety problem. The haptic sensation is provided by varying the viscosity of the magnetorheological fluids by adjusting the magnetic field, which is dependent on the force measured in the slave manipulator. Therefore, three parts of the haptic interface were designed and fabricated: magnetic field, magnetorheological fluids container and haptic performance calibration mechanism. Some preliminary experiments have been done to verify the effectiveness of this kind of haptic interface. Experimental results illustrated that the designed haptic catheter operation system can be used for teleoperation and for training the surgeon for the non-experience.