CurrentevidenceshowsthatapolipoproteinE(APOE),apolipoproteinCI(APOC1)andlowdensitylipoproteinreceptor-relatedprotein(LRP)variationsarerelatedtolate-onsetAlzheimer’sdisease.However,itremainsunclearifgeneticpolymorphismsinthesegenesareassociatedwithcognitivedeclineinlate-onsetAlzheimer’sdiseasepatients.Weperformeda30-monthlongitudinalcohortstudytoinvestigatetherelationshipbetweenAlzheimer’sdiseaseandAPOE,APOC1,andLRP.Inthisstudy,78ChineseHanpatientswithlate-onsetAlzheimer’sdiseasewererecruitedformGuangxiZhuangAutonomousRegioninChina.APOE,APOC1,andLRPgenotypingwasperformedusingpolymerasechainreaction-restrictionfragmentlengthpolymorphisms.TheMini-MentalStateExaminationandClinicalDementiaRatingScalewereusedtoassesspatients’cognitivefunction.Aftera30-monthfollow-upperiod,wefoundasignificantreductioninMini-MentalStateExaminationtotalscore,ahigherproportionofpatientsfulfillingcognitiveimpairmentprogressioncriteria,andahigherproportionofAPOC1H2carriersinAPOEε4carrierscomparedwithnon-carriers.Inaddition,theAPOEε4allelefrequencywassignificantlyhigherinthecognitiveimpairmentprogressiongroupcomparedwiththenon-cognitiveimpairmentprogressiongroup.Inconclusion,APOEε4playsanimportantroleinaugmentingcognitivedecline,andAPOC1H2mayactsynergisticallywithAPOEε4inincreasingtheriskofcognitivedeclineinChinesepatientswithlate-onsetAlzheimer’sdisease.