To evaluate the appl ication value of internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement for the treatment of tuberculosis of lumbosacral vertebral body. Methods From March 2000 to February 2005, 16 cases of spinal tuberculosis in L3-S1 were treated with internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement. Sixteen cases included 11 males and 5 females, and the age was 21-56 years. The locations of spinal tuberculosis were L3 in 4 cases, L4 in 6, L5 in 4, and S1 in 2. The course of disease averaged 13 monthes (range 6 monthes to 6 years). The ESR of all cases was greater than 20 mm/h (average40 mm/h); WBC was normal in 14 cases, and a l ittle high in 2 cases. The X-ray picture showed narrow intervertebral space in 5 cases, compressed body of vertebra in 7 cases, and destroyed 2 consecutive vertebra and its sclerotin was condupl icate in 1 case. All cases were abscess in major psoas muscle. The CT showed destruction of bone, abscess-formation and dead bone in body of vertebra of 16 cases. The abscess were found in vertebral canal in 5 cases and dura mater of spinal cord and spinal nerve root crushed in 2 cases. The MRI showed destruction of bone, abscess-formation and hibateral abscess in major psoas muscle in 11 cases. The abscess were found in vertebral canal and dura mater of spinal cord and spinal nerve root crushed in 6 cases. The therapy of pasid was treated after operation in all the cases. Results Incision healed by first intention in 16 cases; and disruption of wound occurred and heal ing was achieved after symptomatic treatment in 1 case. Sixteen cases were followed up 2-5 years (29 months on average). Among all the cases, anaesthesia in double thigh was found in 3 cases, adynamia of dorsiflexion in foot in 1 case, gatism in 1 case; after 2 weeks the symptoms were vanished. Indirect hernia of fold inguen were found in 1 case after 2 years, and the patient refused operation for age and was no longer followed up. Fuzzy, exsic and acerb in eyes were foundin 6 cases, hearing disturbance were found in 2 cases, and symptoms were vanished after medication adjustment. Low-grade fever and lumbar myalgia were found in 1 case and cured after staying in bed and medication adjustment. All ESR were normal, synostosis of lumbosacral vertebral body was found in 13 cases, kyphosis in 1 case. Conclusion Internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement is safe and available way for the treatment of tuberculosis of lumbosacral vertebral body, it can save the times of operation, shorten period and enhance effect of treatment.