"Normal" spinal posture is generally accepted as moderate lordosis of the cervical and the lumbar sections of spine an moderate kyphosis of the thoracic and sacrococcygeal sections. Among these normal range of the lumbar lordosis is less well defined. CT is very useful method to identified the bony structure and adjacent soft tissue of the spine , so it is very available method to detect accurate lumbar lordotic angle by using lateral Scanogram. Analysis andcomparison of lumbar lordotic angles, crossing angle are drawn each parallel line to the superior end plate of body of 1st. lumbar vertebra and to the inferior end plate of the 5th . lumbar vertebra, in 174 cases with backache and 50 cases normal groups at Kangnam General Hospital Public Corporation, from Aug. 1985 to Jul 1986. Male and female were almostly same affected in backache group(1.1 : 1). And most lumbar lordotic angles were 10$^{circ}$ to 40$^{circ}$ between all backache age group. On backache group, over all mean lumbar lor otic angles were 24.7$pm$8.9$^{circ}$ but no significant difference at mean value of the each disease, such as HIVD, Degenerative Spondylosis or No Remarkable Findings group. On control group, over all meanones were 29.2$pm$8.0$^{circ}$. So, significant difference of lumbar lordotic angle between backache and control group, and most difference is at 5th, decade group(p.0.01).p(p.0.01).