Abstract The volatile composition of the root oils of ten Bupleurum species (B.chinense DC., B.scorzonerifolium Willd., B.microcephalum Diels., B.malconense Shan et Y. Li, B.longicaule Wall. et DC. var. giraldii Wolff, B.marginatum Wall. ex DC, B.bicaule Helm, B.yinchowense Shan et Y. Li, B.wenchuanense Shan et Y. Li, B.smithii Wolff. var. parvifolium Shan et Y. Li) have been studied. The species were collected in their typical habitats of China. The oils were obtained by hydrodistillation and their analyses were performed by GC/FID and GC/MS. Fifty constituents of the oils were identified. The major components of the root oil of B.chinense were hexanal (29.5%), furfural (7.3%), hexanoic acid (7.4%), 2-amylfuran (5.5%) and (E,E)-2,4-decadienal (5.9%). The main components of the root oil of B.scorzonerifolium were hexanal (12.4%), furfural (8.1%), heptanal (9.3%) and dodecanoic acid (5.7%). Sixteen compounds were characterized in the root oil of B.microcephalum, with cyperol (15.6%), heptanal (6.4%) as main constituents. The major components were furfural (13.2%) and p-tolyl-2-propene (7.5%) in the oil of B.malconense. Nineteen compounds were characterized in the root oil of B.longicaule, with hexanal (15.1%), furfural (15.6%) and p-tolyl-2-propene (7.2%) as main constituents. The main constituents were p-tolyl-2-propene (9.2%), p-cymene (8.4%) and cis-linalool oxide (5.4%) in the root oil of B.marginatum. Nineteen compounds were characterized in the root oil of B.bicaule, with 4-tridecen-6-yne (42.6%) as the main constituent. The main compounds were hexanal (30.5%), furfural (11.9%) and hexanoic acid (11.7%) in the root oil of B.yinchowense. The main components were undecane (19.9%), p-tolyl-2-propene (8.5%) and hexanal (6.1%) in the root oil of B.wenchuanense. Twenty-two compounds were characterized in the root oil of B.smithii var. parvifolium, with hexanal (10.8%) and methyl thymol (6.2%). A comparison of the root oil compositions from the ten Bupleurum species showed that the concentration of major compounds was different, but almost all samples were found to contain a series aliphatic derivatives.