Objective To investigate the changes and clinical significance of serum kynurenine(KYN)and quinolinic acid(QA)levels in elderly patients with chronic kidney disease(CKD)complicated with major ad-verse cardiovascular events(MACE).Methods A total of 156 elderly patients with CKD treated in the Fourth People's Hospital of Taizhou from February 2022 to February 2024 were selected as the CKD group,and were divided into the MACE group(n=45)and the non-MACE group(n=111)according to whether they were complicated with MACE.A total of 80 healthy people who underwent physical examination in the Fourth People's Hospital of Taizhou during the same period were selected as the control group.High perform-ance liquid chromatography-tandem mass spectrometry was used to measure the serum KYN and QA levels in each group.Multivariate Logistic regression was used to analyze the risk factors for MACE in elderly CKD pa-tients.The receiver operating characteristic curve was used to analyze the predictive value of serum KYN and QA for MACE in elderly CKD patients.Results The levels of KYN and QA in CKD group were higher than those in control group(P<0.05).The age,levels of C-reactive protein,24 h urinary protein,KYN and QA in MACE group were higher than those in non-MACE group(P<0.05).The increased levels of 24 h urinary protein,C-reactive protein,KYN and QA were risk factors for MACE in elderly CKD patients(P<0.05).The area under the curve(AUC)of combined detection of serum KYN and QA for predicting MACE in elderly CKD patients was 0.920(95%CI 0.891-0.959),which was greater than the AUC of KYN[0.836(95%CI 0.804-0.879)]and QA[0.843(95%CI 0.798-0.887)]alone,and the difference was statistically significant(Z=4.023,3.897,P<0.05).Conclusion The levels of serum KYN and QA are increased in elderly CKD pa-tients with MACE,which are related to renal function.The combination of serum KYN and QA can effectively predict the risk of MACE in elderly CKD patients.