A new celastraceae alkaloid, euojaponine C has been isolated from the methanol extract of the root bark of Euonymus japonica. With the relative stereochemistry of euojaponine C established by NOESY data, the absolute stereochemistry has been determined by circular dichroism (CD) exciton chirality method. The CD of the 2, 5-bis-phenyl benzoate of triacetonide derived from the LiAlH-4 hydrolysate, euonyminol shows that the configuration of C-2 and C-5 are both R.