['Currently degeneration of the intervertebral disc and joint in the degenerative process of the lumbar spine has mainly attracted the attention, however, there are very few literatures focusing on the height of the spinous process. Our objective was to examine in what generation the change in spinous process height occurs and how the change is involved in the degenerative process of the lumbar spine.', 'CT or CT myelography of 1,015 patients, 536 males and 579 females were measured in 6 items, including the heights of the L4 and L5 vertebral bodies, the L4 and L5 spinous processes, the L4/5 intervertebral disc, and the L5/S1 intervertebral disc. All data of the 6 items were analyzed and compared between gender in 5 age groups (40s, 50s, 60s, 70s and 80s).', 'The results indicated a significant increase in the height of the L4 and L5 spinous process (P < 0.01) in the 60- to 70-year-old group for both genders, and also showed that the L4 and L5 vertebral body height was significantly decreased in the 50- to 60-year-old group (P < 0.01 in males, P < 0.001 in females).'] Is an increase in height of spinous process associated with decreased heights of intervertebral disc and vertebral body in the degenerative process of lumbar spine?