Objective: To analyze and study the relationship between ApoE gene polymorphism and cardio-cerebrovascular complications in type 2 diabetes mellitus(T2DM) in the Chinese Population. Methods: From January 2018 to January 2019, 1140 patients with type 2 diabetes admitted to the Department of Endocrinology, the Affiliated Hospital of Xuzhou Medical University were selected as the case group, including 590 patients with coronary heart disease(CHD) and 550 patients with cerebral infarction(CI), and 1198 patients with type 2 diabetes without complications during the same period were selected as the control group. General baseline data of the two groups were collected, such as gender, age, course of disease, lipid profile, HbA1C, BMI, blood pressure, carotid plaque and complications. ApoE genotypes were identified in all participants who participated in the study.Results: This study showed that the ApoE genotypes in both the case group and the control group had the highest frequency of E3/E3. The E3/E4 genotype frequency and E4 allele frequency in the case group were higher than those in the control group (P<0.05). In the case group, the frequency of E2/E3 and E3/E4 genotypes of CI group was lower than that of CHD group, while the frequency of E3/E3 genotype was higher than that of CHD group. TC and LDL-c levels were significantly increased in patients with ApoE E3/E4 genotype(P<0.05). ApoE genotype E3/E4 was more associated with carotid plaque than E2/E3. ApoE genotype and ApoE allele were positively correlated with TC and LDL-c levels (P<0.05).Logistic regression results show that ApoE gene polymorphism is associated with cardio-cerebrovascular complications in T2DM patients. ApoE E3/E4 genotype and allele E4 may be risk factors for T2DM patients with cardio-cerebrovascular complications.Conclusion: ApoE E3/E4 genotypes and T2DM patients carrying E4 allele have a higher risk of cardio-cerebrovascular complications than other genotypes. ApoE E2 allele has a certain protective effect , however E4 allele may be a risk factor for cardio-cerebrovascular complications in T2DM patients, and its mechanism may be related to the effect of ApoE gene on lipid metabolism.