Abstract: A cardio assist system has an integrated cardio-assist catheter including a multi-lumen tube and an inflatable/deflatable balloon provided on a distal end portion of the tube, a blood pump connected to the proximal end of a main lumen in the catheter, and a balloon driver for supplying and discharging a gas to and from the balloon so as to repeatedly inflate and deflate the balloon. Disclosed also is a device for inserting the cardio assist system to a living body safely, accurately and promptly. A combined use of the cardio assist system and the insertion device enables a quick set up a strong assisted blood circulation system.