Local structure of phospholipid/amine polyion complexes in lyophilized powders of dipalmitoylphosphatidic acid(DPPA)/poly-L-lysine(pLYS) and DPPA/poly-L-arginine(pARG) is investigated by solid-state nuclear magnetic resonance spectroscopy. The intermolecular interactions in the polyion complexes were detected by P-31-H-1 heteronuclear shift correlation (HETCOR). The complete information about the P-31 chemical shift tensor (CST), principal values of CST and the mutual orientation of CST with respect to a molecular fixed frame, for methylguanidinium dihydrogenorthophosphate (MGD/H2PO4), which is thought of as a model compound for DPPA/pARG, was determined by both cross-polarization and magic-angle sample spinning (CPMAS) and spin-echo separated local field (SLF) measurements under the magic-angle sample spinning (MAS). From the ab initio P-31 chemical shielding calculation, the behavior of the principal components of P-31 chemical shield tensor in the phosphate group in DPPA is found to be dominated by a change in the electronic state in association with phosphate/amine complexation, rather than by a change in a bond angle of nonprotonated angle O-(3)-P-O-(4) which was previously deduced in several phosphate compounds.