Objectives: To investigate the occupational and genetic risk factors inducing lumbar disc degeneration in a Chinese population, and to explore their synergistic interactions. Methods: A case-control study involving 178 low back pain patients with lumbar disc degeneration and 284 controls was carried out. Five types of work-related factors were investigated using questionnaires. Polymerase chain reaction and restriction fragments length polymorphism was used to detect the polymorphisms of MMP-3 (matrix metalloproteinase-3)(rs731236), VDR-Taq (vitamin D receptor-Taq) and VDR-Apa (vitamin D receptor-Apa)(rs35068180). Rothman's synergy index was used to measure the synergistic interactions between gene polymorphisms and occupational risk factors. Results: Family history of lumbar disc diseases, back injury history, whole-body vibration, bending/twisting, heavy physical workload, age, mutation alleles 5A of MMP-3 and A of VDR-Apa were significantly associated with lumbar disc degeneration (OR=12. 70, 11.79, 8.96, 5.46, 1.05, 1.96 and 1.70, respectively, p<0.05). Synergistic interactions existed between the mutation allele 5A of MMP-3 and wholebody vibration exposure, the mutation allele 5A of MMP-3 and bending/twisting, and the mutation allele A of VDR-Apa and bending/twisting (SI=13.27, 2.91, 2.35, respectively, p<0.05). Conclusions: The results of this study suggest that gene-occupation interaction might play a certain role in exaggerating lumbar disc degeneration. There is a possibility that subjects who carry mutation alleles 5A of MMP-3 and/or A of VDRApa are more vulnerable to lumbar disc degeneration when they are exposed to whole-body vibration and/or bending/twisting under ergonomic loads. It is estimated that 15% to 20% of adults have back pain during a single year, and 50% to 80% experience at least one episode of back pain during their lifetime 1) . Jin 2) reported that the incidence of low-back pain (LBP) was as high as 50% in an investigation of one population of Chinese workers. Lumbar disc degeneration is considered to be a primary cause of LBP 3,4) . The pathogenesis of lumbar disc degeneration includes radial fissures, rim tears in the annulus, and loss of water content in the nucleus pulpous and annulus. These changes are suspected of underlying many back pain symptoms.The etiology of lumbar disc degeneration is complex, and recent research on the causes of disc degeneration have shed light upon a better understanding of the risk factors contributing to disc degeneration. Magora 5) suggested that occupational factors contributing to the acceleration of spinal degeneration included heavy physical loads, manual materials handling consisting of lifting, bending and twisting, prolonged sitting, sustained non-neutral work postures, and vehicle driving. Videman 6) confirmed that occupational exposures are viewed as the primary source of the mechanical factors