Spondylolithesis is defined as forward slipping of a vertebral body on distal vertebra, and this slipping causes a spectrum of symptoms from mild back pain to overt spinal stenosis. The various treatment modality for spondylolisthesis is introduced. In general, the slip of lesser than 50 per cent can be successfully treated with in situ fusion in children and early adolescent without neurologic deficit. Operative reduction of spondylolisthesis may be indicated in cauda equina syndrome, progressive slip surpassing 40 to 50 per cent, major deformity causing decompensation or distress, major pain or deficit plus two or more risk factor. Risk factors for in situ fusion include the following: slip angle greater than 25 degrees, trapezoidal L5, rounded sacral end plate, hyperlordosis exceeding 50 degrees L2- S1, L5 radiculopathy requiring decompression, female adolescents, excess lumbosacral mobility, sign of sacral root stretch. Stabilization after decompression of high grade isthmic spondylolisthesis is difficult due to insufficiency of fusion base, gap between the bases and incompetent anterior disc support. So posterior lumbar interbody fusion(PLIF) offered anterior support, reduction of the deformity and a broad fusion base may be applied. PLIF may be indicated in spinal stenosis with narrow neuroforaminal space, isthmic spondylolisthesis with instability after removal of posterior structure of vertebra, grade 3,4 isthmic spondylolisthesis, failure of posterolateral fusion, symptomatic degenerative disc disease.