PURPOSE: To provide a new platinum (IV) complex of a cyclohexanediamine derivative represented by a specific formula, and useful for the therapy of organ tumors including cerebral tumor because of being excellent in antitumor action and high in fat solubility.

CONSTITUTION: The complex represented by formula I {group of formula II in formula I is 1,2-cycloalkandiamine of formula III [n is 1-4; steric structure is cis(R, S-), trans-d(1S, 2S-), trans-l(1R, 2R-)], 2-aminomethylcyclohexylamine of formula IV [cis-l(R, R-), cis-d(S, S-), trans-l(R, S-), trans-d(S, R-)], 1,1- diaminomethylcyclohexane of formula V, o-phenylenediamine, ethylendiamine, propylenediamine; X is Br, I, F; B1, B2 are ligands forming an o,o-oriented 5 or 6-membered ring with platinum (IV)}.