Three new isostructural coordination polymers, namely, [Mg(cpna)(H₂O)₂]_n (1), [Mn(cpna)(H₂O)₂]_n (2) and [Co(cpna)(H₂O)₂]_n (3) (H₂cpna = 5-(3-carboxylphenyl)nicotic acid) are reported. They were synthesized by hydrothermal reactions of transition metal or alkaline earth metal chloride with 5-(3-carboxylphenyl)nicotic acid, respectively. Complexes 1～3 exhibit 2D layers with a 3,3-connected topology with Schläfli symbol {4.8²}. Such layers including hexagonal rings and a quadrangular ring are further extended into an ordered 3D framework by hydrogen bonds between the cpna^2- ligands and water molecules. The rare complex 1 has excellent luminescence and can be used as luminescent materials, while 2 and 3 possess prominent magnetism with potential applications in magnetic materials.