The weak hydrogen bond interactions of two stereorisomeric flavanols (catechin and epicatechin) and proline, one of the most abundant amino acids in salivary proteins, have been theoretically investigated by the DFT methods with bases 6-31 G (d,p) and 6-31 + G (d,p). Geometric, energy and spectroscopic parameters were calculated. These confirm the formation of complexes by moderate hydrogen bonds between the hydroxyl groups of catechin or epicatechin with the heteroatoms Nsp3, Osp2 and Osp3 of proline. Also, this study establishes that the complexes formed with the proline heteroatoms Nsp3 and Osp2 are the most stable.