A series of palladium complexes with 2,2'-bipyridine and 1-(substituted benzyl) azetidine- 3, 3-dicarboxylates as ligands were synthesized and characterized by IR, (1)H-NMR, ESI-MS spectra and elemental analysis. The in vitro cytotoxicity assays were carried out against A549, HCT-116, HepG-2 and SGC7901 cancer cell lines. The result showed that most of the complexes possessed moderate antiproliferative activity against HCT-116, HepG-2 and SGC7901 cell lines. Complex 12 (with 2,2'-bipyridine and 1-(3-methoxylbenzyl)azetidine-3,3-dicarboxylate as ligand) was the most potent antitumor agent among all thirteen complexes, which showed comparable or better cytotoxicity against all four tested cancer cell lines than carboplatin. The interaction between complex 12 and pET22b plasmid DNA was investigated by agarose gel electrophoresis, and the result of the study showed that complex 12 had no obvious interaction with the plasmid DNA.