The objective of the study reported here was to develop a master slave system for catheter-guided vascular surgery conducted by interventional radiology. By using a master slave system, the surgeon is not exposed to x-rays during the operation because the master tool managed by an operator is located away from the slave tool, which is near the patient. The system must provide vivid realism to the surgeon, particularly with regard to force information, because this surgery is performed in three dimensions while the surgeon watches a two-dimensional monitor. In this study, we developed a training system for a catheter guide in order to upgrade the surgeon's skills because it is difficult to upgrade a master slave system without training. The system consists of a human interface device as the master tool, a control box, and a simulator. This training simulator is for the master slave system, which we developed. The master tool has a force display function using an electrorheological fluid. Two advantages of the fluid actuator are that it can be used without force feedback control and there is mechanical safety, as the surgeon does not experience any accidental force. An open loop control is used to achieve a simple mechanism and algorithm. Our results of preliminary experiments indicated that the output force achieved correlated with that sent from the PC. Three surgeons evaluated this training system under a variety of conditions. The operation of the master tool is simple. The thrust and rotation movements of the catheter can be handled instinctively and without complicated instructions. In addition, accurate force display, response, and stability were achieved with the electrorheological fluid. In the future, the training will need for a realistic depiction of interventional radiology, and the system provides accurate readings for aspiration and blood flow.