Objective To explore the expression and effect of interleukin18 (IL18) in patients with vacuum of lumbar intervertebral disc. Methods 66 patients with vacuum found in intervertebral disc were classified into the observation group well the other 71 patients without vacuum found in intervertebral disc were classified into the control group. The expression of IL18 in serum as well as the proteoglycan in the nucleus pulposus token from the two group were tested through enzymelinkedimmunosorbentassay (ELISA). Nucleus pulposus cells were treated with variousconcentrations of IL-18 (0ng/mL, 50ng/mL, 100ng/mL, 200ng/mL). The transcriptionallevel of Matrix metalloproteinase-3 (MMP-3) were tested by RT-PCR. Proteoglycan in the cell supernatant was tested by Alcian blue method. Then the expression of MMP-3, p-p65, p65, IL-1β and TNFα were studied by Western-blot. Results The expression of IL18 in the observation group (214.74 ± 19.11 pg/mL) was higher than that in the control group (50.90 ± 37.62 pg/mL) (P＜ 0.05). However, the expression of proteoglycan in the observation group (52.415 ± 0.201 mg/g) was lower than that in the control group (161.415 ± 7.652 mg/g) (P＜0.05). After treated with IL18, the transcriptionallevel of MMP3 in the nucleus pulposus cells increased as the increase of the concentrations of IL-18 (P＜0.05). The expression of proteoglycanin the nucleus pulposus cells were 2097.65 ± 23.10 mg/L，1088.54 ± 33.09 mg/L，767.04 ± 73.81 mg/L，531.65 ± 55.19 mg/L which decreased as the increase of the concentrations of IL18 (P＜0.05). The expression of MMP-3, pp65, IL-1β and TNFα were increased as the increase of the concentrations of IL.18, however the expression of p65 decreased. Conclusion The expression IL-18 in patients with vacuum of lumbar intervertebral disc was high. It actives the NFκB signal path to promote the expression of MMP-3 and inflammatory factors such as IL1β and TNFαwhich father prevent the biosynthesis of proteoglycan, so that to take part in the progression of vacuum of lumbar intervertebral disc.