Objective To study the effect of homocysteine(Hcy)on the formation of atherosclerotic and acceleration of ApoE-/-mice liver lipid metabolism disorder .Methods 12 normal 5 weeks old C57BL/6J mice served as control group ,and 36 5 weeks old C57BL/6J A poE-/- mice were randomly divided into 3 groups(n=12 for each group) ,the model control group ,the hyperhomocys-teinemia(HHcy)group and the intervention group(intervened by folate and vitamin B12 ) .18 weeks later ,the blood of the mice was gotten using a Unilateral enucleation method ,and the Serum Hcy and lipid changes were detected by Biochemical analyzer .And the changes of plaque size were measured by HE staining .The liver tissues of the 4 groups mice were taken and the changes in hepato-cyte lipid were detected by oil red O staining ,and the hepatic lipid levels were measured by enzymatic determination(by Semi-quan-titative image analysis) .Results The results showed that ,when compared with the control group ,the serum Hcy ,LDL ,TG and CHOL levels of the HHcy group significantly increased by 2 .3 ,2 .8 ,5 .0 ,10 .7 fold(P<0 .01)and the content of HDL decreased by 64% (P<0 .01) ,and the result showed that ,conpared with the HHcy group ,the seram Hcy ,LDL and CHOL levels of the interven-tion group were significantly decreased by 43% ,34% ,21% (P<0 .05) .Atherosclerotic fatty plaque could be seen in the hyperlipi-demic ,model and intervention group .Meanwhile ,there was a large number of scattered fat in A poE-/-mice liver by oil red O staining in the HHcy group ,and the CHOL and TG levels were 2 .2 fold and 2 .8 fold higher in the HHcy than that in the normal control group respectively(P<0 .01) .And compared with the HHcy group ,the serum CHOL and TG levels of the intervention group sig-nificantly decreased by 34% ,33% (P<0 .01) .Conclusion It is found that Hcy can induce the formation of As and accelerate liver lipid metabolism disorder .