【Abstract】 Objective To investigate the effect of Tanreqing injection combined with montelukast on serum levels of ET1, Ang II and leptin in children with obstructive sleep apnea syndrome. Methods 88 children with obstructive sleep apnea syndrome in our hospital from June 2013 to August ~2015 were selected and randomly divided into control group and experimental group. Each group had 44 cases. All the children admitted to the hospital were treated with conventional treatment. On the basis of this treatment, the control group was given Tanreqing injection, and the experimental group was treated with montelukast based on the control group. The clinical efficacy of the two groups was compared. Before and after treatment, LSaO2, MSaO2, AHI, TS90%, serum ET1, Ang II, and leptin were compared. Results The effective rate of the experimental group (9545%) was higher than that of the control group (7273). The difference was statistically significant (P＜005). AHI, TS90%, serum ET1, Ang II and leptin of control group and experimental group decreased significantly. The experimental group was significantly lower than the control group (P＜005). LSaO2 and MSaO2 of control group and experimental group increased significantly. The experimental group was higher than the control group (P＜005). Conclusion Tanreqing injection combined with montelukast is effective in the treatment of obstructive sleep apnea syndrome, and can effectively reduce the levels of serum ET1, Ang, II, and leptin.