Sex reversal syndrome is a kind of human genetic disease about gender dysplasia, which is characterised by inconsistency between gonadal sexuality and chromosome sexuality; the incidence rate was about 1:20,000-100,000. The clinical manifestations, hormonal levels and cytogenetic findings in a patient of 46, XX male sex reversal syndrome retrospectively were analysed and related published reports were reviewed. The DNA fragments of sex-determining region Y (SRY) gene from the patient was found by polymerase chain reaction, but the fluorescent in situ hybridisation analysis revealed that the SRY translocated from Y to X chromosome. We concluded that the Y chromosomal SRY gene is required for the regulation of male sex determination. The detection of SRY is important for the clinical diagnosis of sex reversal syndrome. Translocation of SRY to X chromosome or other autosomes would be one of the key factors that induced XX male SRS.