Abstract: Objective To study the relationship between polymorphism of ApoE and mild cognitive impairment(MCI).Methods The patient of MCI was filtered in the survey and the case 2control study was made.All of the objects were geno-typed for ApoE by allele-specific PCR(ASPCR)and detected for glycerol trinitrate(TG)、cholesterol(TC)、high density lipoprotein(HDL).Results Univariable Logistic regression analyses showed that sex(OR=1.859,95%CI=1.016～3.402),age(OR=2.044,95%CI=1.454～2.872),marriage status(OR=2.713,95%CI=1.428～5.152),occupation (OR=5.485,95%CI=2.710～1.1099)and ApoEε4 carrying(OR=2.641,95%CI=1.430～4.879)were related to MCI.In Multivariable analyses,age(OR=2.228,95%CI=1.511～3.287),employment(OR=5.854,95%CI=2.741～12.501),and ApoEε4(O R=2.573,95%CI=1.296～5.217),ApoEε2(OR=0.288,95%CI=0.091～0.905)were possible risk factors for MCI.In addition,there was interaction between AopEεr and LDL.Conclusion Age,employment,and ApoEε4 may increase the risk of MCI,while ApoEε2 tends to decrease it.The interaction between ApoEε4 and LDL plays an important role in probing into the mechanism of the polymorphism of ApoE incurring disease.