Two complexes [Pd(L₁)(en)]₂·4H₂O (1), [Pd(L₂)(en)]·2H₂O (2), (L₁ = pyridine-2,3-dicarboxylic acid, L₂ = pyrazine-2,3-dicarboxylic acid, and en = ethylenediamine) have been synthesized and characterized using IR, ¹H NMR and element analysis. X-ray analyses of complexes 1 and 2 revealed that 1 belongs to the triclinic system with space group P(2), and 2 belongs to the monoclinic system with space group P2(1)/n. The binding of the complexes with HC-DNA (HeLa cells DNA, which was extracted by ourselves) were measured by fluorescence spectrum and viscometry. Gel electrophoresis assay demonstrates the ability of the complexes to cleave the extracted HC-DNA. The complexes exhibit a higher cytotoxicity against tumor cells as against normal cells in vitro. Further more, apoptotic tests indicate that the complexes have an apoptotic effect on HeLa cells.