A new complex,[Co-2(OH)(2)L-2(phen)(2)(H2O)(2)]2(HL) (1) (HL = 2-fluoroisonicotinic acid, phen = 1,10-phenanthroline), has been synthesized using the slow-layered diffusion technique at room temperature. Single crystal X-ray analysis revealed that complex 1 is a dinuclearcobalt(II) complex connected by hydroxyl oxygen. The thermal stability was studied by thermogravimetric analysis (TGA). In addition, the variable-temperature magnetic property of the complex has been also discussed. The negative, J or -E2/k values can be indicative of an overall antiferromagnetic coupling in addition to single-ionspin-orbital coupling.