According to one embodiment, a memory system includes a nonvolatile memory including first blocks configured to store an address indicating a data storage position, and second blocks configured to store the data, a first table configured to store a first address including first information and second information, the second information indicating a data storage position in the first block, and a second table configured to convert the first information into third information, the first information having a first data size by which one entry of the second table can be identified, the third information having a second data size which is larger than the first data size and by which one of the first blocks and the second blocks can be identified.