Objective To explore the relationship between lumbar disc degeneration (LDD) of lumbar spinal stenosis(LSS)and the dural sac cross-sectional area(DSCA)by MRI measurement. Methods 91 patients with central degenerative LSS were randomly selected and 91 age-and sex-matched people without LSS were select-ed as a control group. LDD was classified into five grades by MRI detection according to the method proposed by Pfirrmann and DSCA were measured. Results LDD was not associated with age in LSS. The proportion of severe degenerated disc in lower lumbar levels were higher than that of L2/3 in the two groups;DSCA in severe degenerat-ed disc group was significantly smaller than that in light degenerated group only in L2/3 and L3/4 in LSS. There were no statistical differences in every lumbar level in the control group. Conclusions LDD in L4/5 and L5/S1 of LSS is more severe than that of the normal people. DSCA and LDD are positively correlated in L2/3 and L3/4,but not in L4/5 and L5/S1 for LSS.