In recent years, requests for automotive comfort are increasing, and the development of seats that cause little fatigue, even for long distance driving, has been required. Until now, seat riding comfort has been studied mainly using dynamic vibration analysis; and there are few studies that give importance to the sensory characteristics of the driver and passengers. In order to apply to the design of comfortable seating, we developed a new seat evaluation method that emphasizes the interaction between the human body and seat. For static seating comfort, we determined seat compliance as a new evaluation index by using a human body pressure distribution that is calculated by dividing the seat into 16 segments, and is related to seat flexion. For dynamic riding comfort, speed of the human body pressure distribution, and the acceleration of each human body part were made into an index. Third, for long-term sitting fatigue, physiological data such as stress hormone density and electromyogram data also were made into an index. Finally, to quantify the conventional sensory evaluation, we matched our physical and physiological data with sensory evaluation data.