Pharmaceutical composition comprising a biguanide derivative as an active ingredient for preventing or treating glioblastoma

Provided is a pharmaceutical composition comprising biguanide derivative as an effective component for preventing or treating glioblastoma. A compound represented by chemical formula 1 and pharmaceutically acceptable salts thereof can be used to prevent or treat glioblastoma. Also, a use of the compound represented by chemical formula 1 in combination with temozolomide provides excellent efficacy in comparison to the administration of the compound represented by chemical formula 1 only, or temozolomide only.