A nonvolatile memory device includes first to N-th memory blocks, wherein N is an integer and N≧3. Each memory block, of the first to N-th memory blocks comprises first to (M−1)-th strings, wherein each string, of the first to (M−1)-th strings, includes drain-side memory cells, source-side memory cells, and a pipe transistor connecting the drain-side memory cells and the source-side memory cells, where M is an integer and M≧2, and an M-th string, including drain-side memory cells formed adjacent to the first string, of a first to (M−1)-th strings, and including source-side memory cells formed adjacent to an (M−1)-th string of the first to (M−1)-th strings.