A semiconductor memory device includes: a plurality of banks each including a plurality of cell mats and a plurality of sense amplifiers shared by adjacent cell mats; and a bank control circuit suitable for activating a normal word line of a particular cell mat of a bank selected according to a refresh command including bank information, and activating a target word line of a cell mat that does not share a sense amplifier with the particular cell mat according to a target refresh command after a preset delay time.