Fuente: WIPO "tomato" The present invention relates to an ionic compound, a pharmaceutical composition for treating cancer comprising the ionic compound, and method for preparing the ionic compound and the pharmaceutical composition. More specifically, it relates to a pharmaceutical composition for treating cancer: which comprises an ionic compound in which two different compounds, each different from the other, selected from ascorbic acid, dichloroacetic acid and lactate are combined with one metal ion; has better therapeutic effect by overlapping and complex disturbances of cancer cell metabolism because different compounds are simultaneously uptake into cancer cells and each acts through different mechanisms on cancer cells, compared to the conventional anticancer drugs focusing on one specific mutation or cancer cell growth signal; and can more effectively inhibit the proliferation, invasion and metastasis of cancer cells because it is less susceptible to drug.