Four tetradentate ligands were prepared by reacting salicylaldehyde with different aromatic diamines in acidic medium (Schiff-base reaction). F.T.IR, 1H-NMR and Maldi- MS techniques were employed to identify the L1 (1,4-bis(N-o-hydroxybenzylidine)phenylene diamine)and L2 (4,4-bis(o-hydroxybenzylidene)biphenyl- amine) molecules, while only F.T.IR and 1H-NMR spectra were used in the identification of L3 (4,4-bis(o-hydroxybenzylidene)methylene-dianiline)molecules. Electron ionization mass spectrometry measurements were carried out to identify L4 (4,4-bis(o-hydroxybenzylidene)aminodi-phenylether) molecules in addition to both F.T.IR and 1H-NMR techniques. A set of coordination polymers was prepared by reacting the tetradentate ligands with nitrate salts of Cu(II), Ni(II) and Co(II). The prepared coordination polymers were identified using F.T.IR, UV-Vis. spectroscopy and magnetic susceptibility measurements. The results indicated that all polymers were octahedral. The prepared polymers were also shown to be insoluble in most polar and non-polar organic solvents.However, the polymeric nature was concluded taking into account amorphousity and stability proved by x-ray diffraction studies for CuL1, NiL1 and CoL1 samples.The DC-electrical properties were studied; the results showed that the semi conductive properties were to be improved by inserting a metal ion into the polymeric chains. Also, Cu-polymers were shown to have the higher conductivities than the other type of polymers.