To provide an aqueous pharmaceutical preparation of a platinum complex which has no fear of contaminating a compounder with a drug with cytotoxicity, can be prepared by a simple operation, has a compact size, and is suppressed from deteriorating of drug during a long-term storage, an aqueous pharmaceutical preparation of a solution of a platinum complex in a stable state, in which an aqueous solution containing a platinum complex is contained in an oxygen-permeable container, and the oxygen-permeable container is contained in an oxygen-barrier container, the preparation being characterized in that the gap between the oxygen-barrier container and the oxygen-permeable container is filled with gas containing oxygen.