Abstract
In order to find a criteria of a double-leg circle for training, the variety of performance is considered based on the mechanism of a double-leg circle. As a result, this variety of a rotation around body axis comes from an existence of a horse body and its pommels as obstacles to be got over by legs. Especially, the relation between the tiptoe position and the hip twisting timing are important for this variation. The described performance for smooth movement for a double-leg circle is attained by synchronization between tiptoe position and the hip rotation around its axis.