Abstract: The synthesis of sixteen new analogs of cis-platinum (CDDP) and seven known Pt analogs, as well as the antitumor activity of seven Pt analogs against solid sarcoma 180 are reported. The new congeners consist of Pt (Ⅱ) and Pt (Ⅳ) complexes containing primary amine ligands (eg· NH3, en, pren) with variable anionic ligands such as malonate and 2-substituted malonates. In the experimental antitumor activity tests, 7 new platinum complexes were given on days 1～7, 24 hours after implanted with 10⁶ cells of solid sarcoma 180 tumor and producedT/C (treated/control) value between 15～35% with less toxicity than the parent cisplatinum. The experimental data indicate that it is favorable to introduce certain hydrophilic groups into the platinum complexes, in the view of increasing their aqueous solubility and lowering their toxicity while retaining their effectiveness.