The use of a biomarker SM(d18:1/24:1(15Z)) in the preparation of an agent or a kit for diagnosing mild cognitive impairment. A method for diagnosing and treating mild cognitive impairment, wherein the diagnosis method is used for determining whether a patient has mild cognitive impairment by detecting the content of biomarkers SM(d18:1/24:1(15Z)) and TG(16:0/18:0/18:4(6Z,9Z,12Z,15Z)), PC(P-16:0/22:4(7Z,10Z,13Z,16Z)) or PC(P-18:0/18:4(6Z,9Z,12Z,15Z)).
METHOD FOR DIAGNOSING AND TREATING MILD COGNITIVE IMPAIRMENT AND USE THEREOF