The synthesis and characterization of a novel chiral phosphine-phosphoric acid ligand, (R)-3-diphenylphosphino-1,1'-binaphthyl-2,2'-diyl hydrogenphosphate (2) and its rhodium(I) complexes are described. The single-crystal X-ray diffraction analysis of 2 showed the intermolecular hydrogen-bonding network of the phosphoric acid moiety. The reactions of 2 with [RhCl(cod)] 2 in the presence of KOtBu or with [Rh(acac)(CO) 2 ] (acac = acetylacetonate) gave P,O-chelating rhodium(I) complexes [Rh(2-H +)(cod)] 3 or [Rh(2-H +)(CO)] 2 4, respectively. Their molecular structures were determined by single-crystal X-ray diffraction.