Nonvolatile memory devices and methods of forming the same are provided, the nonvolatile memory devices may include first regions and second regions which extend in a first direction and are alternately disposed in a semiconductor substrate along a second direction crossing the first direction. Buried doped lines are formed at the first regions respectively and extend in the first direction. The buried doped lines may be doped with a dopant of a first conductivity type. Bulk regions doped with a dopant of a second conductivity type and device isolation patterns are disposed along the second direction. The bulk regions and the device isolation patterns may be formed in the second regions. Word lines crossing the buried doped lines and the bulk regions are formed parallel to one another. Contact structures are connected to the buried doped lines and disposed between the device isolation patterns.