Introduction: Loss-of-function mutations in or gain-of-function duplications of the gene encoding MeCP2 at Xq28 cause severe neurological disorders. The aim of this study is to delineate the clinical and hereditary characteristics of MECP2 duplication syndrome in Chinese patients. Methods: A retrospective study was conducted to examine 5 Chinese patients with Xq28 duplications syndrome in our department. Results: All of the patients were male, the ages ranged from 1 year and 4 months to 8 years. All of the patients exhibited severe motor and language developmental delay, autism spectrum disorder and recurrent infections. Two patients exhibited refractory epilepsy. Two patients exhibited cardiovascular abnormalities. One patient exhibited hemophagocytic syndrome (HPS). One patient exhibited precocious puberty. Brain MRI scans in all of the patients was abnormal manifested as encephalomalacia, corpus callosum dysplasia, and fifth and sixth ventricle formation. Electroencephalography in 3 patients displayed epileptiform activity or slow wave. By CGH microarray analysis, duplication sizes in these patients range from 0.473 to 1.013 Mb, and all the duplications included MECP2, IRAK1, HCFC1 and L1CAM. Duplication of SLC6A8 was included in the duplication regions of 3 patients. Duplication of FLNA gene was included in duplication regions of 2 patients. Conclusion: Although the clinical phenotypes of MECP2 duplication syndrome were nonspecific, most patients exhibited severe motor and language developmental delay, autism spectrum disorder and recurrent infections. HPS and precocious puberty were first reported in this syndrome. CGH microarray analysis is important for patients with developmental delay, autism spectrum disorder and recurrent infections to accept early diagnosis.