Aspects of the disclosure provide the memory system having a memory apparatus and a memory controller coupled with the memory apparatus. The memory apparatus includes at least one memory chip having a plurality of memory planes, each memory plane includes a plurality of pages, a plurality of pages located at the same position in each of the memory planes of the at least one memory chip form a page line, the memory apparatus includes a plurality of tag groups, each tag group includes a plurality of page lines. The memory controller can be configured to, when the memory apparatus is powered down and then powered on, respectively perform, in sequence, a recoding operation on all pages of which the states are programmed states in each tag group, and according to an encoding result corresponding to each tag group, respectively determine whether check data corresponding to each tag group is abnormal.