The hydrothermal synthesis, single crystal X-ray structure and magnetic properties of a new cobalt(II)-carboxy-cinnamate complex is described. Reaction of Co(II), carboxy-cinnamic acid (C10H8O4) and NaOH at 120degreesC yield the coordination network, Co(H2O)(2)carboxy-cinnamate (1). 1 crystallizes in the monoclinic system, a= 11.3236(4), b= 6.6084(4), c= 7.201](6) Angstrom, beta= 101.948(5)degrees, V= 527.2(1) Angstrom(3), space group P2(1)/c, Z = 2. 1 possesses a three-dimensional coordination-bonding network consisting of layers Of CoO6 bridged by the tetra-dendate carboxy-cinnamate. Its magnetic moment decreases on lowering temperature due to spin-orbit coupling and no interaction between cobalt ions is observed.