An oxidizing agent useful for oxidative polymerization of high conductive polymers is provided. This oxidizing agent is a kind of organic metal complex formed of metal ion salts having oxidizing capability and nitrogen-containing compound having lone pair electrons with partial π-electron character. This organic metal complex has weak oxidizing strength for monomers at room temperature. As such, a mixture of the organic metal complex and the monomers has long-term stability under room temperature. While, at a high temperature, the organic metal complex provides proper oxidative polymerization capability for the monomers. The conductive polymers synthesized by the organic metal complex have excellent conductivity.