In spite of numerous clinical and patho-anatomical studies made in the past there are still different opinions concerning the mechanism the mechanism of low back pain. We have focused attention on the posterior structures as an alter-native source of low back pain with sciatica. So we have studied and analyzed the finding of arthrography of facet joint and effect of the injection of mehtyiprednisolone acetatate suspension(Depomedrol) 20mg into the each facet joint. Our results are as follows: 1.Abnormal findings of facet joint arthrogram were degenerative osteoarthritis of facet joint (70.5%) synovial cyst (11.8%) accessory bone (11.8%) and spondylolysis (5.9%) 2. The mean facet angulation of patients of facet syndrome were abnormal on lower lumbar facet joint in 9 of 13 cases (69.2%) 3. On initial assessment 11 of 17 cases(64.7%) showed complete relief and one month later 6 of 11 cases (35.5%) showed continous relief after steroid injection.