Abstract: Objective：To evaluate the correlation of IL-13 promoter region 1112C＞T and CYP3A4*1G gene polymorphisms with the susceptibility of penicillin allergy. Methods：A case control study involving in 211 patients with penicillin allergy and 220 healthy controls from Gansu province was performed. The distributions of IL-13-1112C＞T and CYP3A4*1G allele and genotype frequency were determined by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP), and χ² test was used for correlation analysis after a representative sample was confirmed by Hardy-Weinberg test. Results: There were statistically significant differences in the frequencies of CC, CT and TT genotypes and C and T alleles of IL-13-1112C＞T between the patients with penicillin allergy and healthy controls (χ²=9.280 and 10.257, P＜0.05). The CT + TT genotype frequency (50.2%) and T allele frequency (28.9%) in the patients with penicillin allergy were significantly higher than those in healthy controls (35.0%, χ²=10.235, P＜0.05; 20.0%, χ²=9.280,P＜0.05). When stratified by gender, there was difference in males between the two groups (χ²=9.215 and 9.525, P＜0.05) but not in females. However, there was no significant difference in the genotype and allele frequencies of CYP3A4*1G between the two groups (χ²=1.169 and 0.360, P＞0.05). When stratified by gender, there was also no significant difference in either males or females between the two groups. Conclusion ：IL-13-1112C＞T gene but not CYP3A4*1G may be related to the susceptibility of penicillin allergy, and the correlation more appears in male patients.