School of Chemical Sciences, Mahatma Gandhi University, Kottayam-686 560, Kerala, India E-mail : pkrkn@yahoo.co.in Manuscript received 12 January 2009, revised 20 July 2009, accepted 20 August 2009 Two series or complexes of two Schiff bases, 2,3-dimethyl-4-formyl-[2'-(aminomethyl)pyridine]-1-phenyl-3- pyrazolin-5-one (L1) and 2,3-dimethyl-4-formyl(benzhydrazlde)-1-phenyl-3-pyrazolin-5-one (L2), with the general compositions [Ln(L1)2(CIO,V2](CIO4) and [Ln(L2}2(CIO4)](CIO4)2 (where Ln = Y, La, Pr, Nd, Sm, Eu, Gd, Dy, Ho or Er) have been synthesized and characterized, Both L1 and L2 are neutral ligands coordinating through the carbonyl oxygen(s) and the azomethine nitrogen In these complexes. Two perchlorate ions are bidentately coordinated in the complexes of L1 and one perchlorate ion is bidentately coordinated in the complexes or L2. A coordination number or eight is assigned to the metal In both series or complexes.