Abstract： Objective To investigate and analyze the effect of body mass index(BMI)on early changes of blood pressure and cardiac structure and function in the elderly.Methods The clinical data of 108 elderly patients who underwent health examination in the Provincial Hospital Affiliated to Shandong First Medical University from May 2020 to September 2022 were retrospectively analyzed.All patients received height and body mass measurement,and their blood pressure and cardiac ultrasound were monitored.They were divided into emaciation group(33 cases),normal group(31 cases),overweight group(25 cases)and obese group(19 cases)according to dif-ferent BMI.The blood pressure levels and cardiac function structural indicators of patients with different BMI were compared for analysis of variance;multiple linear regression analysis was used to investigate the correlation between BMI and early blood pressure and cardiac structure and function indicators in the elderly.Results There were significant differences in systolic blood pressure,diastolic blood pressure,left ventricular mass index(LVMI),left ventricular posterior wall thickness of end-diastolic(LVPWTd),left ventricular pos-terior wall thickness at end-systole(LVPWs),left ventricular end-systolic diameter(LVESd),left ventricular end-diastolic diameter(LVEDd),interventricular septum thickness(IVSs),and left ventricular ejection fraction(LVEF)among the lean,normal,over-weight,and obese groups(P<0.05).Multiple linear regression analysis showed that BMI was positively correlated with systolic and di-astolic blood pressure,and LVMI,LVPWTd,LVESd,LVPWs,LVEDd,IVSs,and it was negatively correlated with LVEF(P<0.05).Conclusion The blood pressure and cardiac structure and function of the elderly with different BMI showed significant differ-ences;BMI level had a significant effect on early blood pressure and cardiac structure and function indexes,and with the increase of BMI,the blood pressure and cardiac structure and function of the elderly would change correspondingly.