Objective：To investigate the relationship between polymorphisms of matrix metalloproteinases（MMP）-9（rs3918242 and rs17576）and silicosis susceptibility of male workers who exposed to industrial dust with silicosis in Hongzhou，Hunan province. Methods：This case-control study included 186 silicosis patients and 186 individuals exposed to industrial dust but without silicosis（the control group），who were strictly matched with the case group for age，gender，work type and cumulative length of dust exposure. The rs3918242 and rs17576 polymorphisms of MMP-9 were detected in all participants using polymerase chain reaction-restriction fragment length polymorphism（PCR-RFLP）. Meanwhile，plasma levels of total MMP-9 were analyzed by ELISA. Results：Frequencies of C/C，C/T and T/T genotypes of MMP-9 rs3918242 locus were 38.7%，34.4%，and 26.9% in the case group，significantly different from frequencies of 57.5%，25.8%，and 16.7% in the control group，respectively（P < 0.05）. Frequencies of C and T alleles were 55.9% and 44.1% in the case group，significantly different from frequencies of 70.4% and 29.6% in the control group，respectively（P < 0.05）. Frequencies of C/T，T/T genotype and T allele in the case group were significantly higher than those in the control group. There was no significant difference in the distribution of rs17576 loci genotype and allele frequency between two groups（P > 0.05）. Furthermore，frequencies of T allele of silicosis patients in theⅡand Ⅲ stages were significantly higher than those of the control group，and circulating levels of total MMP-9 were also significantly higher in subjects with T allele than those in subjects with CC genotype. Conclusion：MMP-9 rs3918242 polymorphism is significantly associated with silicosis and the severity of pulmonary fibrosis，and the polymorphism of rs17576 loci may not be related to silicosis susceptibility.