The structures of three novel binary acridone alkaloids, glycobismine-A 1, -B 4, and -C 4, from the root and stem barks of Glycosmis citrifolia (Willd.) Lindl. (Rutaceae) collected in Taiwan were elucidated via spectroscopic techniques including ¹H-¹³C long-range correlation spectroscopy (COSY) and heteronuclear multiple bond correlation (HMBC). As part of a continuing investigation of acridone alkaloids from the genus Glycosmis (known to produce various monomeric acridones), these alkaloids were isolated by fractionating an ethanolic extract using silica gel column chromatography and preparative thin-layer chromatography (TLC). Glycobismine-A 1, the first naturally occurring binary acridone with a carbon-carbon linkage between its two moieties, was characterized as yellow needles (m.p. 256–258 °C, [α]₀ +0) with the molecular formula C₃₁H₃₂N₂O₆ (via high-resolution mass spectrometry). Its structure, along with those of glycobismine-B 4 and -C 4, was determined using additional methods: ultraviolet (UV) and infrared (IR) spectroscopy (revealing 1-hydroxy-9-acridone nuclei), ¹H and ¹³C NMR (including proton decoupling and ¹H-¹H COSY to assign proton systems), methyl iodide derivatization (yielding an N,O,O,O-tetramethyl derivative), and nuclear Overhauser effect (NOE) experiments (confirming the angular orientation of a fused 2,2-dimethyl-3,4-dihydropyran ring). This work provides the complete spectroscopic elucidation of glycobismine-A 1 and the structures of the two additional binary acridones.