Abstract: AimTo study the chemical constituents of the water-extracts of the pine needles of Pinus massoniana Lamb.. MethodsPine needles were collected in Xixia country and extracted with boiling water for two times and the water-extracts were concentrated. The crude extract of pine needles was fractionated into four fractions by Et₂O, EtOAc and n-BuOH. Various column chromatography with D-101 macroreticular resin, Toyopearl HW-40 and silica gel were employed for the isolation and purification of compounds from the n-BuOH fraction of pine needles. The structures of the compounds were identified by physiochemical properties and spectral analysis (UV, IR, MS, ¹HNMR, ¹³CNMR, DEPT, HMQC, HMBC, etc.). ResultsFour compounds were isolated from the n-BuOH fraction of water-extracts, and their structures were identified as 3-methoxyl-9′-O-α-L-rhamnopyranosyl-4′:7,5′:8-diepoxyneoligan-4,9-diol (massonianoside E, I), 4,4′,8,8′,9-pentahydroxyl-3,3′-dimethoxyl-7,9′-monoepoxylignan (II), umbelliferon (III), 4-(4′-hydroxyl-3′-methoxylbenzyl)-2-butanone (IV). ConclusionCompound I is a new compound, and compounds II, III and IV were isolated from this plant for the first time.