Eight coordinated complex samples of CoCl2-NaDC were obtained,using various concentration and initial molar ratio of CoCl2 and NaDC. They exhibited distinct appearances and characters. Their different structures and components were investigated by FTIR spectroscopy, X-ray diffraction analysis and ICP analysis. We can give the following conclusions: (1) when the concentration of NaDC is smaller than C.M.C, Co2+ ions react with mono-molecular NaDC and the component of the pink wadding-like resultant is Co(DC)2 x 3H2O. (2) When the concentration of NaDC is larger than C.M.C, and the concentration of CoCl2 is higher (0.5 mol/L), Co2+ ions destroy NaDC micelles, and the component of the pink wadding-like resultant is also Co(DC)2 x 3H2O. (3) When the concentration of NaDC is larger than C.M.C, and the concentration of CoCl2 is lower (0.1 mol/L or more lower), Co(DC)2 and NaDC may form mixed micelles, and some of NaDC micelles connect with each other through the Co2+ bridges to produce complicate Co(DC)2-NaDC complex with gel character and macromolecular network structure. In human body,the concentration of metal ions is usually lower and the concentration of NaDC is larger than C.M.C, So the third kind is suggested as an ideal model of the interaction between Co2+ ions and NaDC in vivo.