Abstract: Objective To assess the effect of Silencor after Silencor was used on child patients with OSAS by the variation of upper airway and AHI. Methods Seventeen child patients (3-12 years old) with OSAS were included between 2008 and 2011 from Nanjing Maternity and Child Health Care Hospital and E.N.T. Department of Jiangsu Provincial Hospital of TCM, who were classified into mild group, moderate group and severe group according to AHI. Cephalometric analyses were carried out before and after the treatment to examine the variation of PNS-R, PNS-UPW, SPP-SPPW, U-MPW, TB-TPPW, V-LPW. All patients underwent polysomnography for twice to evaluate the therapentic effect by AHI at the first visit and after the improvement of subjective symptoms. Results SPP-SPPW, U-MPW, TB-TPPW increased significantly in mild and moderate child patients with OSAS after treatment. AHI decreased significantly in mild and moderate child patients with OSAS after treatment. Conclusion Silensor can enlarge the upper air way, which is positive for child patients with mild or moderate OSAS.