Hydrothermal reactions in the system of Ni(II), 1,3,5-benzenetricarboxylic acid (btcH(3)), and 4,4'-bipyridine (bpy) with or without naphthalene produced three new coordination polymers, [Ni-2(bPY)(3)(btcH)(2).(H2O)].(H2O) (2), [Ni-2(bpy)(2)-(btcH)(2)].(C10H8)(3) (3), and Ni(bpy)(btcH(2))(2) (4), in addition to previously reported [Ni-2(bpy)(2)(btcH)(2)](C10H8)(0.75)H2O (1). Polymer 2 is the only product when naphthalene is absent in the reaction, and it is composed of 2D layers of coordination polymers with guest water molecules between them. When naphthalene is added to the system, compounds 1, 3, or 4 are formed depending on composition. Compound 3 has a 3D framework structure with naphthalene guests, and 4 has a 1D chainlike structure with no guest. Details of the synthesis condition and crystal structures of each compound are discussed. Crystallographic data: 2, C2/c, a = 22.500(3) A, b = 20.053(3) A, c = 19.625(3) A, beta = 99.314(3)degrees; 3, P2(1)/c, a = 11.248(2) A, b 16.801(4) A, c = 14.945(3) A, beta = 103.732(4)degrees; 4, C2/c, a = 10.692(2) A, b = 11. 114(3) A, c 21.962(5) A, beta = 106.268(11)degrees