The 2-picolinate complexes M(C5H4NCOO)2?xH2O of cobalt(II) and nickel(II) were synthesized with cobalt acetate, nickel chloride and 2-pyridinecarboxylic acid as the reactants by solid-state reaction at room temperature. The compositions and structures of the complexes were characterized by EDTA titration, elemental analysis, FT-IR spectrum, X-ray powder diffraction, thermogravimetric and differential thermal analysis. The results of characterization showed that the cobalt(II) and nickel(II) were coordinated by the heterocyclic nitrogen atoms and carboxyl oxygen atoms of the ligands, and oxygen atoms from the water molecules, respectively. Thermal decomposition processes of the complexes included dehydration, oxidation and pyrolysis of the ligand, and finally as metallic oxide.