Snowboarder's motion is seemingly complex. We have made a snowboarding robot which has flexion and extension in an ankle joint. One servomotor was attached to the ankle joint for dorsi-flexion and plantar-flexion.This model leans to the side of the flexed ankle from a basic posture. This posture is an inward-leaning postureof a turn. It is this motion which causes the snowboard to be edged. The edging of the snowboard changesaccording to this movement. To make a toe-side turn, it flexes the ankle (dorsi-flexion) and to make a heel-sideturn, it extends the ankle (plantar-flexion). A carving turn can be performed by using a side-cut snowboard. Thismodel is also capable of achieving a sequential turn. The width of board is found to be significant in maintaininga stable sequential turn. Too narrow a board makes a change of the edged side unstable. It turns out that thewidth of the snowboard plays an important role in allowing the model to make stable repeated turns.