Abstract: The present invention relates to a new use of Hades as a tumor suppressor target, more particularly to a composition for suppressing tumor comprising an expression or action inhibitor of Hades protein having an amino acid sequence of SEQ ID NO: 2 as an effective ingredient. The present inventors have found that the overexpressed Hades protein interacts with p53 to inhibit the exonuclear mechanism of p53 and the knowdown of Hades induces increase in the expression of p53, demonstrating that Hades is a negative regulator to p53. Therefore, it would be understood that the inhibition of Hades overexpressed in tumor cells contributes to tumor-supressive effects of p53. The drug candidates capable of modulating the expression of the Hades protein, inhibiting the actions of the Hades protein or inhibiting interecation between Hades and p53 are considered a promising anticancer drug.