A new octadecanoyl diterpenoid glycoside,(E)-8α,15-dihydroxy-15-(3S-hydroxy-octadecanoyl)-13-labdene-8-O-α-L-arabinopyranoside(1),was isolated from the aerial parts of Conyza blinii,and the structure was identified on the basis of a detailed spectroscopic analysis,including 2D NMR spectrometry and HRESI-MS.