3-Nitrolawsonemonoxime, 3-aminolawsonemonoxime and their chelates of Ca(II), Mg(II), Sn(II), Pb(II) and Zn(II) have been synthesized and their antibacterial activity studies were carried out. The results obtained were analysed to find the effect of change in concentration of test compounds, change in the substituents at C-3 position in the quinonoid ring of the ligand and the effect of change of central metal ion.The NO2 group at C-3 position in the quinonoid ring of the ligand showed greater activity than NH2 group. The activity of 3-nitrolawsonemonoxime was found to be decreased while that of 3-aminolawsonemonoxime, was observed to be increased due to chelation. In case of the chelates, activity was increased if their concentrations were increased sufficiently (doubled). But in case of Ca(II)-3-aminolawsonemonoximate, generally there has been no change in the activity with concentration. Elemental analysis andTG indicated ML22H2O molecular composition for the chelates.