Abstract: Objective To study the expression and its significance of MMP-8、Col-Ⅰ、Col-Ⅲ mRNA in hepatic tissue in oral arsenic solution exposed mice.Methods 50 mice werer divided into control group,sodium arsenite group and sodium arsenate group at random.Sodium arsenite group and sodiumarsenate group were made by 300 mg/L per day of so diumarsenite and sodium arsenate respectively.The mice were sacrificed after 10 months for liver function and pathologic examination.The expression of MM p-8,TIMP-2,Col-Ⅰ、Col-Ⅲ mRNA were detected with real time flourescence quantitative PCR.The result was contr olled with 18s.Results Serum ALT、AST、GLB of arsenic exposed mice were higher than that of nomal mice.Pathologic examination showed that there were notable liver cell necrosis,regeneration and a little fibrosis.The expression of Col-Ⅰ、Col-Ⅲ mRNA in sodium arsenite group were higher than the nomals(t_Col-Ⅰ=5.49,t_Col-3 =8.64,P<0.05);MMP-8 mRNA in so diumarsenite group were lower than the normals(t=7.35,P<0.05);The expression of TIM P-2,Col-Ⅰ、Col-Ⅲ mRNA in sodium arsenate group were higher than the normals(t_TIMP-2=6.72,t_Col-Ⅰ=5 49,t_Col-3=8.64,P<0.05);MMP-8 mRNA in sodium arsenate group were lower than the normals(t= 6.28,P<0.05).Conclusion Exposed to arsenic solution orally,could result in hepat ic injury and hepatic fibrosis in mice and the TIMP-2,MMP-8 gene play significant effect in process of hepatic fibrosis.