Abstract: Objective To analyze the correlation between serum 25-hydroxy vitamin D and children's wheezing.Methods During January 2014 to December 2016, in Liwan Hospital of the third Affiliated Hospital of Guangzhou Medical University, 60 children with asthma who cured in department of pediatrics were enrolled as experimental group, and 57 healthy children who received physical examination at the same time were enrolled as the control group, the levels of serum 25 hydroxyl vitamin D were compared between the two groups. According to whether the children in the acute exacerbation of the disease, the children in the experimental group were divided into two subgroups:experimental group 1 (acute exacerbation stage) and experimental group 2 (stable phase), levels of serum 25 hydroxyl vitamin D in the two subgroups were compared.Results The level of serum 25-hydroxy vitamin D in experimental group was (20. 08 ± 4. 21) ng/m L which lower than that in control group (43. 14 ± 6. 36)/m L, the difference was statistically significant (P< 0. 05). The level of serum 25-hydroxy vitamin D in experimental group 1 was (14. 05 ± 2. 88) ng/m L, which was lower than that in experimental group 2 (26. 09 ± 3. 10) ng/m L, the difference was statistically significant (P< 0. 05).Conclusion The decrease of serum vitamin D level was one of the risk factors of children's wheezing.