Abstract: Objective　To explore the effect of sublingual immunotherapy (S-LIT) on the balance of Th17/Treg in children with mite allergic asthma. Methods　All 124 cases with mite allergic asthma were randomly divided into two groups, the control group (62 cases) was treated with ladder type inhalation, and the treatment group (62 cases) was administered of dust mite drops on the basis of conventional treatment. The peripheral frequency of Th17 cell and Treg cell of all the subjects (before and after treatment) were detected by flow cytometry,  the serum cytokine IL-10、IL-17 levels wer analyzed by ELISA. Results　After 1 year treatment,  the Th17 cells in treatment group (1.50 %±0.87 %)  was significantly lower than that before treatment (3.39 % ± 1.58 %), and less than that of the control group after 1 year of treatment (2.42 %±1.32 %) (P <0.01)；after 1 year treatment, the proportion of Treg cells in treatment group (4.05 %±1.36 %) was significantly higher than that before treatment (2.33 ± 0.81%), and more than that of the control group after 1 year of treatment (2.87 %± 0.87 %) (P <0.01). After 1 year treatment, the serum IL-10 levels in treatment group (64.76±27.79 pg/mL) was significantly higher than that before treatment (36.32 ± 11.53 pg/mL), and more than that of the control group after 1 years of treatment (50.32 ± 10.97 pg/mL) (P <0.01)；after 1 year treatment, the serum IL-17 levels in treatment group (20.45±8.35 pg/mL) was significantly lower than that before treatment (86.48 ± 28.19 pg/mL), and significantly less than that of the control group after 1 year of treatment (46.32 ± 12.43 pg/mL) (P <0.01). After 1 year treatment, the Childhood Asthma Control Test (C-ACT）score in the treatment group (24.35 ± 8.47) was significantly higher than the control group (20.13 ± 6.86) (P <0.05). Conclusions　SLIT can decrease airway inflammation and correct the imbalance of Th17/Treg in children with mite, allergic asthma.