To investigate the correlation between the polymorphisms of apolipoprotein E(APOE), the interleukin-1 alpha (IL-1 alpha ) genes and the susceptibility to Alzheimer's disease(AD).Association study was performed in 114 AD patients and 113 healthy elderly individuals from Chengdu, China. Polymorphisms of APOE and IL-1 alpha genes were analyzed with polymerase chain reaction-restriction fragment length polymorphism.The frequency of APOE-epsilon 4-carrying genotype in moderate to severe AD patients (28.6%) was higher than that of mild patients (18.5%) and the controls (14.2%), and the difference between moderate to severe AD group and the control group was significant (OR=2.4, 95%CI: 1.1-5.5). The frequency of epsilon 4 was also of significant difference between the group of moderate to severe dementia and the control group (OR=2.6, 95%CI: 1.3-5.3). However, no significant difference in distribution of IL-1 alpha polymorphism between AD patients and controls was observed.The APOE epsilon 4 allele was associated with moderate to severe AD while no association between the IL-1 alpha gene polymorphism and AD was found.