Noonan syndrome is a common genetic disease characterized by peculiar face, short stature, congenital heart disease and thoracic deformity. The pathogenesis of Noonan syndrome is mainly related to abnormal Ras-MAPK signal pathway which involves more than 16 genes including (PTPN11, SOS1, RAF1)] and KRAS. At present, there is a lack of experience in the diagnosis and treatment of Noonan syndrome in China. This guideline has summarized the clinical manifestation, pathogenesis, diagnostic criteria and treatment for Noonan syndrome, with an aim to improve the diagnostic level and clinical management of patients with this syndrome.