This paper reports the synthesis and characterstics of a tridentate ligand N,N di(2' benzimidazolyl methyl) imide (IDB) and two containing manganese (Ⅱ) mononuclear complexes [Mn(IDB) 2]Cl 2·CH 3OH·H 2O(Ⅰ),[Mn(IDB) 2](ClO 4) 2·CH 3CH 2OH·H 2O(Ⅱ).Based on the elemental analyses,molar conductivity,UV Vis,middle and far IR spectra,it is infered that coordination geometry of these two complexes may be close to a typical square pyramidal or octahedral. These two complexes are better struc...