A new series of DNA binding 5, 10, 15-tri (N-methyl-4-pyridiniumyl) porphyrin (TrisMPyP)- platinum (II) conjugates was synthesized, in which different spacer ligands were used for appropriate coordination to platinum (II) complexes. Compound 9b exhibited in vivo antitumor activity (T/C%, 294) superior to cisplatin (T/C%, 184) against the leukemia L1210 cell line.