Objective To investigate the relationship between IL-13 gene + 2044G / A polymorphism to the risk of asthma in children and its relevancy of serum IL-13 levels. Methods Ninty cases of children with bronchial asthma (asthma group) and 82 healthy children (control group) were recruited. PCR-RFLP and ELISA were used to detect IL-13 gene 2044G?＞?A polymorphism and serum IL-13 levels. Genotype, allele frequencies and the corresponding serum IL-13 level were calculated. χ2 test and t-test were used to compare the genotype, allele frequency, and serum IL-13 level between the two groups. Results The distribution of IL-13 gene 2044G?＞?A polymorphism showed significant difference between the two groups. Compared with AA genotype and A allele, children with GG genotype and G allele were associated with an increased  risk of bronchial asthma, and the OR value were 3.706 (95%CI:1.059~12.976) (P ＜ 0.001) and 2.525 (95%CI:1.532~4.159) (P ＜ 0.001). The level of serum IL-13 is higher in asthma group than in control group (Z = 7.899, P ＜ 0.001), and the serum IL-13 level of GA and AA in asthma group is higher than that in children with  GG genotype (Z = 5.555, P ＜ 0.001; Z = 3.541, P ＜ 0.001; Z = 2.777, P ＜ 0.05). Conclusion There is association between IL-13 2044G?＞?A polymorphism and serum IL-13 level in children' with bronchial asthma. And A allele maybe associated with higher serum IL-13 level in children with asthma.