Objective To investigate the correlation between carotid plaque (CP) and age-related decline of renal function in healthy individuals. Methods A retrospective cohort study was conducted on 449 subjects who visited Department of Geriatrics or took physical examination in Physical Examination Center in Huashan Hospital Affiliated to Fudan University from January 2016 to January 2019. Their clinical data, including CP, renal function, blood pressure, and blood glucose and lipids were collected at baseline, and CP and renal function were detected regularly during the follow-up, which was completed in June 2023. According to their age at baseline, they were divided into a young group (<60 years, n=286) and an elderly group (≥60 years, n=163). Subjects were divided into CP group (n=153) and non-CP group (n=296) according to whether CP was present at the time of enrollment. Based on the changes in CP at baseline and follow-up, they were assigned into four groups:Group 1 (without CP at baseline or follow-up, n=244), Group 2 (without CP at baseline but newly developed at follow-up, n=52), Group 3 (with CP at baseline but disappeared CP at follow-up, n=26) and Group 4 (with CP both at baseline and follow-up, n=127). SPSS statistics 26.0 was used for data analysis. Depending on data type, student′s t test, one-way analysis of variance, Mann-Whitney U test or Chi-square test was used for intergroup comparison. Logistic regression model was employed to identify the influencing factors for CP. Results The elderly group had significantly higher incidence of CP (53.4% vs 25.2%), increased systolic blood pressure (SBP), and elevated levels of cholesterol (CHO), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), uric acid (UA) and glycosylated hemoglobin A1c (HbA1c), but lower hemoglobin (Hb) level and decreased estimated glomerular filtration rate at baseline (baseline-eGFR), when compared with the young group (P<0.05). Advanced age, increased SBP, higher levels of CHO, TG, LDL-C and UA, but lower high-density lipoprotein-cholesterol (HDL-C) level and baseline-eGFR were observed in the participants with CP at baseline than those without CP (P<0.05). At the end of follow-up, 52 participants developed new plaques (11.6%) and 26 had plaque disappeared (5.6%). Compared with Group 1, baseline-eGFR was lower, its annual decline was increased, older age, higher SBP, and elevated CHO, TG, LDL-C, UA and HbA1c levels were observed in Group 2 (P<0.05). Similarly, lower baseline-eGFR level, obvious increase of annual decline of eGFR, older age, higher SBP, and raised CHO, LDL-C and UA were found in Group 4 when compared with Group 3 (P<0.05). Multivariate logistic regression analysis showed that age (OR=5.098,95%CI 1.125-8.718; P＜0.001),SBP (OR=1.986,95%CI 1.019-3.289; P＜0.001),CHO (OR=1.804,95%CI 1.109-4.597; P=0.018), LDL-C (OR=1.814,95%CI 1.010-1.964; P=0.031), baseline-eGFR (OR=0.974,95%CI 0.907-0.985; P＜0.001)and the annual decline of eGFR (OR=1.228,95%CI 1.014-1.572; P=0.016) were independent risk factors for CP. Conclusion There is an age-related decline in renal function in healthy adults, and eGFR and its annual decline are independent risk factor for CP. In the process of aging, besides active control for blood pressure and blood lipids, regular monitoring of renal function is helpful to prevent the occurrence and development of atherosclerosis.