Abstract: Objective This research mainly aims to explore the correlation between the atherogenic index of plasma (AIP) and carotid arteriosclerosis (CAS) in the middle-aged and the elderly in the community, and to study various risk factors of CAS. Methods A total of 835 middle-aged and aged people (> 45 years old) were collected from those accepted physical examination in the community health service center, including 255 cases diagnosed with CAS by the carotid artery color Doppler flow imaging as the case group, while 321 cases without CAS as the control group. Two groups of subjects were given routine inspections such as blood lipid, liver function and renal function, blood glucose, and blood pressure examination, and abdominal B ultrasound. And the patients also filled the questionnaires and recorded the health of the objects. Results There were statistical differences between CAS group and the control group in BMI, blood pressure, fasting blood glucose, uric acid, etc. AIP index of the CAS group was significantly higher than that of normal control group. Via 18 sets of questionnaire survey, 7 factors showed statistical differences (all P < 0.05), namely history of fatty liver (OR=2.337), history of hyperlipidemia (OR=4.572), BMI > 24 (OR=2.801), history of diabetes (OR=11.133), daily vegetable consumption ≤ 500 g (OR=3.095), history of hypertension (OR=3.421), and regular exercise (OR=0.076), where regular exercise as the protection factor. Conclusion Our research results show that AIP is closely related with CAS in the middle-aged and the elderly in the community and AIP can be used for the measurement of LDL-C diameter and can effectively predict atherosclerosis. Carotid atherosclerosis is also associated with hypertension, diabetes, BMI, and lifestyle.