OBJECTIVE: To probe into the correlation between chitinase 3-like 1（CHI3 L1） gene polymorphism and efficacy of inhaled glucocorticoid in children with bronchial asthma. METHODS: Totally 142 children with bronchial asthma treated in this hospital from 2019 to 2020 were extracted as the observation group and received inhaled glucocorticoid therapy. And 92 healthy children under physical examination during the same period were selected as the control group. Single nucleotide polymorphisms at rs883125

rs4950928

and rs10399805 of CHI3 L1 gene were detected by Mass ARRAY-IPLEX mass spectrometry array method. Forced vital capacity（FVC）

forced expiratory volume in one second（FEV

1

）

FEV

1

/FVC before and after treatment were detected in the observation group by micron MAS-99 pulmonary function tester. The genotype frequency of rs883125

rs4950928 and rs10399805 of CHI3 L1 gene was compared between the observation group and the control group. The genotype frequency of rs883125

rs4950928 and rs10399805 of CHI3 L1 gene was compared in the observation group with different curative effects. The difference of pulmonary function indicators at rs883125

rs4950928 and rs10399805 of CHI3 L1 gene was compared in the observation group before and after treatment. RESULTS: The frequency of GG gene distribution at rs883125 was significantly higher in the observation group than in the control group

the frequency of CC gene distribution at rs4950928 was significantly lower than that in the control group

and the frequency of CG gene distribution was significantly higher than that in the control group

with statistically significant differences（P

<

0.05）

and there was no difference in genotype frequency between two groups at rs10399805（P

>

0.05）. After 12 weeks of inhaled glucocorticoid treatment in 142 children with bronchial asthma

the good control rate was 69.01%（98/142）

the frequency of GG gene distribution at rs883125 in the good curative effect group was significantly lower than that in the poor curative effect group

and the CC gene distribution frequency at rs4950928 was significantly higher than that in the poor curative effect group

with statistically significant differences（P

<

0.05）

there was no statistically significant difference in the genotype frequency of rs10399805 in different therapeutic groups（P

>

0.05）. The difference of CC type

CG type FVC

FEV

1

FEV

1

/FVC at rs883125 was significantly higher than that of GG type

the difference of CC type FVC

FEV

1

FEV

1

/FVC at rs4950928 was significantly higher than that of CG type and GG type

the difference of GG type FVC

FEV

1

FEV

1

/FVC at rs4950928 was significantly higher than that of CG type

with statistically significant differences（P

<

0.05）. There was no difference in the difference of FVC

FEV

1

FEV

1

/FVC at rs10399805 of CHI3 L1 gene in the observation group before and after treatment（P

>

0.05）. CONCLUSIONS: The single nucleotide polymorphisms at rs883125 and rs4950928 of CHI3 L1 gene are related to the efficacy of inhaled glucocorticoid in children with bronchial asthma.