Objective To explore the relationship between haptoglobin gene polymorphism and disease se-verity and susceptibility in senile vascular dementia patients.Methods A total of 80 patients with senile vas-cular dementia admitted to the hospital from February 2018 to February 2023 were selected as the vascular de-mentia group,and 80 stroke patients with non-vascular dementia admitted to the hospital during the same pe-riod were selected as the control group.The genotype distribution and allele frequency of haptoglobin gene were measured using polymerase chain reaction with sequence-specific primers,and their relationship with the severity and susceptibility of vascular dementia patients was analyzed.Results The proportion of history of hyperlipidemia and diabetes mellitus and the levels of total cholesterol and triglyceride in vascular dementia group were higher than those in control group,the differences were statistically significant(P＜0.05).The distribution of genotypes was in Hardy-Weinberg equilibrium(P＞0.05).The frequency of haptoglobin 2-2 genotype and haptoglobin 2 allele in vascular dementia group were higher than those in control group,and the differences were statistically significant(P＜0.05).There were significant differences in the scores of mini-mental state examination and hachinski ischaemic score among patients with vascular dementia with different haptoglobin genotypes(P＜0.05).Multivariate Logistic regression analysis showed that the carrier of hapto-globin 2-2 genotype and the carrier of haptoglobin 2 allele were independent risk factors for vascular dementia(P＜0.05).Conclusion Haptoglobin 2-2 genotype and haptoglobin 2 allele distribution frequency are associ-ated with the occurrence of vascular dementia after stroke,and those with high frequency of haptoglobin 2-2 genotype and haptoglobin 2 allele distribution suffer a severe disease,which can provide reference for early i-dentification and assessment of vascular dementia.