Based on 882 skeletal specimens comprising 444 males and 438 females, the vertebrae of Japanese macaques, Macaca fuscata fuscata, were examined. Numerical variation was determined by counting ribs and by counting facets. No sexual difference was significant in overall distribution of frequencies. The number of cervical vertebrae was invariably seven. The ranges of variation in thoracic, lumbar, sacral, and caudal vertebrae were 12-13, 6-8, 2-4, and 7-11, respectively. The maximum number of caudals exceeds 12, though unconfirmed. The ranges of variation in thoracolumbar, lumbosacral, and thoracolumbosacral vertebrae were 18-20, 9-11, and 21-24, respectively. These variations cannot be fully explained by thoracization, lumbarization, and/or sacralization. The range of variation in vertebrae with thoracic type of prezygapophyseal facets was 8-11, which is wider than that reported previously. Vertebrae are repetitive units with numerical variation. It is impossible to homologize each vertebra among individuals. A new paradigm is needed in order to understand the numerical variation of the vertebral column.