A pharmaceutical anticancer or anticancer drug-resistance composition for a cancer cell, containing a CAGE-derived peptide, is provided. The pharmaceutical anticancer composition contains an effective ingredient of the CAGE-derived oligopeptide with SEQ TD NO.1 or SEQ ID NO.2 and reduces anticancer drug resistance or exhibits an anticancer effect. The pharmaceutical anticancer composition can be employed for a new anticancer drug with advanced anticancer activity of itself, as well as improving a remedy effect with an anticancer drug because of effectively reducing cancer cells, which are resistive to an anticancer drug, and anticancer drug resistance of cancer tissues. The oligopeptide as the effective ingredient of the pharmaceutical anticancer composition is hardly concerned with immunity reaction because of small molecular weight, different from an antibody, and advantageous in effectively overcoming general anticancer drugs because of selective activity to a cancer cell or a cancer tissue.