Rett syndrome (RTT) is a neurodevelopmental disorder mainly affecting the females. It is closely associated with mutations of methylated CpG binding protein 2 ((MeCP2))] gene on the X chromosome. The incidence of RTT in females is 1/15 000 - 1/10 000. Its clinical features include mental retardation, loss of language function, rigid movement of hands, and abnormal gait. Currently there is no cure for the disease but only symptomatic treatment. The compilation of this guideline has referred to the third edition of Diagnostic Standard of RTT as revised in 2010, and integrated the latest findings of clinical research at home and abroad, in addition with conditions and clinical practice in China, with an aim to provide guidance for the clinical diagnosis, treatment and genetic counseling of patients with RTT.