The synthesis of a tetradentate Schiff-base ligand bis(salicylidene)ethylenediamine from salicylaldehyde and ethylenediamine , are important class of ligands . The results of the C.H.N study revealed the formation of a 1:1 [M:L] ratio. .[Er(Salen)(NO3)2]-, square antiprismatic geometry, is the proposed structure of lanthanide metal complex. 1H-NMR, FT-IR, UV-Visible spectral mesurements, and molar conductance were used to estimate the synthesized Schiff-base ligand and its complex. The stoichiometry of the complex has been found to be 1:1 (Er:Salen) matching with C.H.N. analysis. After deprotonation, spectral studies revealed that the ligand was tetradentately coordinated to the metal ion (N2O2) through azomethine nitrogen and phenolic oxygen. The biological activities of the Schiff base (Salen , H2L) and Er(III) complex against E.coli and Staphylococcus bacteria were examined, Schiff base ligand being less active than Erbium (III) complex.