Three novel limonoids, 2,3-dideacetylxyloccensin S (1), 30-deacetylxyloccensin W (2), and 7-hydroxy-21β-methoxy-3-oxo-24,25,26,27-tetranortirucalla-1,14-diene-23(21)-lactone (3), were isolated from the seeds of the Chinese mangrove, Xylocarpus granatum. The structures were elucidated on the basis of 1D- and 2D-NMR (including 1H- and 13C-NMR, DEPT, 1H,1H-COSY, HSQC, HMBC, and NOESY) data and confirmed by HR-MS.