Nonvolatile memory devices including a memory cell array with a plurality of memory blocks and a plurality of bit lines arranged at the memory cell array. Each of the plurality of memory blocks may include a plurality of strings arranged in rows and columns and formed to be vertical to a substrate. Strings of each row of each memory block are connected with the bit lines, respectively, and strings of each column of each memory block are connected in common with a corresponding one of the bit lines. One memory block of the plurality of memory blocks includes a first region for storing ROM data and a second region for storing replica ROM data for repairing the ROM data.