In this paper, the organic ligand hydroxamic acid derivative N-hydroxy-3,4-dimethoxy-N-methylnaphthalene-1-carbothioamide was prepared. Thereafter complexation of the newly synthesized ligand with lanthanoids (III) metal has been completed. The complexation of ligand N-hydroxy-3,4-dimethoxy-N-methylnaphthalene-1-carbothioamide (derivative of hydroxamic acid) with La(III) ion under pH control in (1:3) Molar ratios (M:L) led to the formation of solid complexes which gave analytical data suggested the (1:3) based on elemental analysis, IR and 1HNMR techniques.