Abstract: Psidium guajava Linn. is an evergreen shrub or small tree of Psidium Linnaeus in the Myrtaceae family. One new glycoside (1) together with 3 known meroterpenoids (2-4) and 9 known glycosides (5-13) were isolated from the fruits of Psidium guajava Linn.. The structure of the new compound was elucidated by the spectroscopic data analysis of HR-ESIMS, 1D- and 2D-NMR, and it was named psiguaoside A (1). The known compounds were identified as guajadial (2), 4, 5-diepipsidial A (3), psidial A (4), chrysin-8-C-β-D-glucoside (5), 2, 6-dihydroxy-3, 5-dimethyl-4-O-β-D-glucopyranosyl-benzophenone (6), quercetin-3-O-β-D-glucopyranoside (7), quercetin-3-O-xyloside (8), guaijaverin (9), avicularin (10), guavinoside E (11), guavinoside B (12), guajaphenone A (13). In the bioactivity assay, compound 3 exhibited significant inhibitory activitiy of U87 with IC₅₀ values of 8.379 μmol·L^-1.