Abstract: An octangonal transducer was designed to measured the normal and tangential forces on a single lug with various lug angle, slip and sinkage. The driving torque on the powered shaft of the model lugged wheel was also measured. The normal pull and lift forces and driving efficiency, the effects of lug angle, sinkage and slip on the forces and efficiency were analysed. A single lug had the highest efficiency at 15% slip. Lug forces increased obviously as the lug sinkage increased, but the average lug efficiency was lower as the sinkage increased The lug rotation angle of attaining the peak pull force was about 90°degree and increased with the increase of slip and lug angle. The lift force and the lug efficiency attained their peak value at about 75 and 95～100 degree rotation angle respectively at all slips and lug angles.