On 6 healthy adult males aged 20-30 years, oxygen pulse was observed during carrying sand bags weighting 10, 20 and 30kg on a level treadmill running with speeds of 3,4 and 5 km/hr. The results obtained were as follows. 1. Oxygen pulse during load carrying on a level treadmill was proportionately increased with an increase of work load, average oxygen uptake per minute. Regression equation of oxygen pulse (y: ml/beat) on the average oxygen uptake (x:l/min) required for each grade of work was expressed as y=3.34x + 5.99, sy.x=0.858. 2. Oxygen pulse reached the highest value 2-5 minutes after the start of load carrying, and thereafter it decreased gradually to some extend as the load carrying was continued. Rate of decrease in the oxygen pulse was gerater in lighter works. 3. In lighter works requiring less than 2.0 l/min of oxygen uptake, oxygen pulse was larger in case of carrying a losd by embrace, in both hands and on head than on back or on shoulder.