The main IR bands of the DL-Homocysteic acid was preliminary assigned. The complexes of DL-Homocysteic acid with Na+, K+, Ca2+ were synthesized. Element analysis and TGA-DTA were used to conclude the compositions of these complexes. The FTIR and FT-Raman spectra were studied to distinguish the different coordination structures. The bands of carboxyl, sulfonate and amino groups are all shifted. The peaks of-CH2- also changed a lot. The results indicated that the H-bonding structures among the moleculars were rearranged. The carboxyl and sulfonate groups of DLH both coordinated with the metal ions. And the coordination structure of C=O group in the three complexes were all monodentated.