Three undescribed triterpene glycosides syzybullosides A-C (1–3) along with fourteen known compounds were isolated from the leaves of Syzygium bullockii (Hance) Merr.& L.M. Perry, including six triterpene glycosides (1–6), four phenolics (7–9, 17), four megastigmanes (10–13), and three flavonoids (14–16). The structures of 1–17 were elucidated by extensive spectroscopic analysis, including IR, HR-ESI–MS, 1D and 2D NMR spectra. Compounds 1–10 and 12–17 inhibited nitric oxide (NO) production in lipopolysaccharide activated RAW264.7 cells with IC50 values ranging from 1.30 to 13.70 µM, lower than that of the positive control compound, L-NMMA (IC50 = 33.8 µM).