Syringa is an important woody ornamental plant with lush flowers and aromatic scent.The research on volatile compositions is necessary for floral scent release mechanism,and provides scientific basis for botanical garden application and new varieties breeding.In this study,the floral volatiles emitted from 6 different Syringa species and varieties including S.oblata×S.vulgaris ‘Xiangxue’,S.persica,S.velutina,S.meyeri,S.pubescens subsp.microphylla and S.meyeri ‘Si Ji Lan’ were collected with dynamic headspace method,and then were identified by automated thermal desorption-gas chromatography / mass spectrometry (ATD-GC/MS) technique.The results showed that:(1) the floral volatile components of the 6 different Syringa species and varieties were distinct qualitatively and quantitatively.A total of 80 volatile components were identified,and these compounds belonged to 9 volatile categories including benzenoid and derivative,terpenoid,alcohol,aldehyde,ketone,fatty hydrocarbon,ester,acid,and others.(2) Among the 6 different species,the highest release amount of volatile components was emitted from S.persica,which was almost 1.8 times more than the lowest that from S.meyeri ‘Si Ji Lan’.(3) Except S.oblata×S.vulgaris ‘Xiangxue’,benzenoid and derivative showed the highest release amount among the 9 categories,so benzenoid and derivative was the main volatile category of the floral fragrances.In S.oblata×S.vulgaris ‘Xiangxue’,the release amount of terpenoid was the highest among 9 categories.(4) Among the components,1,3-dimethyl benzene,2-ethyl-1-hexanol,ethylbenzene,p-xylene,butylated hydroxyl toluene,5-ethyl-2,2,3-trimethyl heptane were exhibited higher release amount in these Syringa plants,which suggested that these compounds were main volatile components of lilac flowers.