Tailor-made medicine can be innovated by the technology of UT-Heart. We reproduce the personal heart model from medical data to make a rational diagnosis based on the mechanism of disease. We try a variety of treatments in simulation so that we can choose the best way to cure. For example, in cardiac resynchronization therapy (CRT) it is known that over 30% of patients don’t get batter even if they are provided care. They are called “non-responders”. We can see if the CRT is valid or not in advance, and if it is valid, we can find where we should put the electrodes to get the most potent effect. In case of difficult heart surgery, trying a variety of options in simulation we can compare the resultant dynamics of blood flow, pressure and burden on heart in each surgical option. On the other hand, we can simulate the medication with UT-Heart, so this system is useful for not only tailor-made medicine but also development of drugs. Farther more, UT-Heart has been utilized in developing new defibrillator, auxiliary artificial heart and so on where animal experiment was indispensable before.