To provide a buttocks cushion used by a pregnant woman at all times, thereby preventing a baby from having torticollis at birth.

The buttocks cushion has a front portion inclined forward and downward and held by both knees, and a buttocks mounting portion for positioning buttocks upward from the upper end of a heel of a foot when sitting on heels, and is made from an elastic material. When the pregnant woman holds the front portion between both knees during sitting on her heels, the buttocks are stabilized, the pelvis is stabilized, the spine is kept straight, and the head of the baby is positioned at the bottom at all times, so that the baby is prevented from having torticollis at birth.