RESUMEN
Objective@#To explore the relationship between urinary soybean isoflavone metabolites and sexual development of adolescent girls.@*Methods@#Fifty girls of grade 5 from one primary school in Xingang City who met the inclusion criteria were selected. Sexual characteristic development was assessed and soybean isoflavone metabolites in urine was tested by ultra high speed liquid chromatography tandem mass spectrometry (UPLC MS/MS).@*Results@#Levels of dye xylinone in girls with different stages of sexual development (advanced, normal, and delayed groups) varied significantly[(186.7±24.1，171.8±22.8，155.3±21.6)μmol/mol] ( F =3.53， P <0.05), highest in advanced group. Urinary genistein was significantly higher in menarche group than that of non menarche group[(213.4±22.8，166.3±21.7)μmol/mol] ( t =2.16， P <0.05). Urinary genistein may be associated with early sexual development among adolescent girls.@*Conclusion@#High level of urine genistein may be related to the early sexual development of adolescent girls.