For autonomous scooping operation by wheel loader, a method for adequate arrangement of bucket trajectory will be proposed. In scooping operation of wheel loader by human operator, bucket motion includes several cycles of arm lift and bucket tilt alternately. Consequently, the tip of bucket moves on alternate short path of horizontal and vertical direction. In this paper, relation between resistance force and advancing direction is analyzed theoretically. Advancing direction of the bucket is dominant factor for resistance force on the bucket during scooping. Based on this analysis, simple algorithm for bucket trajectory arrangement is proposed. The algorithm is implemented into small size experimental model of wheel loader. Results of the experiments show that proposed algorithm generates adequate bucket motion for different conditions of pile.