The present work can be divided into two parts :- Part one:- Synthesis of six 2-(arylhydrazone) benzothiazole ligands and their Fe(III),Co(II) and Mn(II) complexes: The six ligands were prepared according to the following steps:- Step-1- :-hydrazinolysis of 2-Mercaptobenzothiazole gave 2-hydrazino benzothiazole . Step-2- :-The new six ligands [Lig1…Lig6] 2-(arylhydrazone )- benzothiazols were synthesized by condensing 2-hydrazino benzothiazole with the appropriate aromatic aldehydes . The structural formulae of these hydrazones are shown below :- where Ar = Step-3- :-Eighteen Fe(III), Co(II) and Mn(II) complexes of the six hydrazones ligands [Lig1…Lig6] were prepared by reaction of the approperiate metal salt with the cooresponding ligand in ethanol under reflux. Part two:- Charactrization of all the prepared compounds: The synthesized ligands [Lig1…Lig6] were characterized on the basis of IR spectral analysis and the results were compatible with their assigned structures . The metal complexes of the hydrazones [Lig1…Lig6] have been charactrized by FT-IR, UV-Vis spectra, conductivity, magnetic susceptibility measurements and metal analysis . On the bases of these techniques the structural and formulae of the complexes have been suggested which were octahedral for all complexes:- 1. The complexes of Fe(III) ion with the ligands [Lig1…Lig6] suggested to have the following molecular formula:- [Fe2(Lig1)2(OH)2(H2O)4] (SO4)2. 3H2O, [Fe(Lig2)(H2O)(SO4)]2 (SO4) [Fe(Lig3)2(H2O)2]2 (SO4)3. 5H2O , [Fe(Lig4)2(H2O)2]2(SO4)3.6EtOH [Fe (Lig5)(H2O)2(SO4)]2 (SO4) , [Fe2(Lig6)(OH)2(H2O)4](SO4)2.2H2O 2.The complexes of Co(II) ion with the ligands [Lig1…Lig6] suggested to have the formula :- [Co(Lig1)(NO3)(H2O)2](NO3).4(H2O),[Co (Lig2) (NO3) (H2O)2](NO3).2H2O [Co(Lig3)(NO3)(H2O)2](NO3),[Co(Lig4)2(H2O)2](NO3)2.EtOH [Co2(Lig5)2(NO3)2(H2O)4](NO3)2.9H2O,[Co(Lig6)(NO3)(H2O)2](NO3).2H2O 3. The complexes of Mn(II) ion with the ligands [Lig1…Lig6] suggested to have a formula :- [Mn2(Lig1)2(OH)2(H2O)4](OH)2.10EtOH, [Mn(Lig2)2(H2O)2](OH)2.6EtOH [Mn2(lig3)2(OH)2(H2O)4](OH)2.3EtOH, [Mn(Lig4)2(H2O)2](OH)2.3EtOH Different bonding and structural behavior were revealed during the study of coordination chemistry of the different new complexes. The Racah and other ligand field parameters which illustrate the bonding nature between metal ion and donor atoms of the ligand were calculated for Co(II) complexes using (Tanabe-Sugano) diagram.