Abstract. [Purpose] Changes in cardiopulmonary function during wheelchair propulsion on a treadmill were measured using wheelchairs according to backrest angle adjustment.[Methods] Twenty-two healthy male subjects were the subjects. Oxygen consumption (VO 2 , ml/min), heart rate (HR, beats/min), carbon dioxide emissions (VCO 2 , ml/ min), oxygen uptake per body weight (VO 2 , ml/kg/min), and respiration frequency (Rf) were used as the measurement variables for cardiopulmonary data.[Results] The peak value, average value and value at rest were compared. When resting, the value did not differ except for VO 2 , and the peak value, did not differ except for VCO 2 . However, the average value in all except VO 2 /kg (at 13 degrees) was significantly lower than 3 degrees (93°).[Conclusion] A 13° wheelchair backrest angle (103°) provides a lower cardiopulmonary workload than the base angle (3°). A training program for good seating and posture needs to be provided