The relationship between 3 polymorphisms sites [interleulin-4 (IL-4), IL-4 receptor (IL-4R) alpha chain and activation-induced cytidine deaminase (AICDA)] and adult allergic asthma in China was studied. By using case-control method, DNA and clinical data were obtained from allergic asthmatic patients and compared with those in the control subjects. The subjects were genotyped for the IL-4 C-589T promoter polymorphism, the IL-4R alpha chain Q576R and the AICDA C8408T by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. The results showed that the IL-4 C-589T was not associated with adult allergic asthma in China. However, the IL-4R alpha chain 576R/R and AICDA 8408T/T frequency was significantly increased in allergic asthma group as compared with that in the control group [odd ratio (OR) = 3.797 and 9.127, respectively; P < 0.01)] and was correlated with the increased plasma total IgE. These data suggested that the IL-4R alpha chain 576R/R and AICDA 8408T/T genotypes confer genetic susceptibility to adult allergic asthma in China.