Provided is a programming method of a nonvolatile memory device. The nonvolatile memory device includes a substrate and a plurality of memory cells which are stacked in the direction perpendicular to the substrate. The programming method applies a first voltage to a selected bit line connected to at least two memory strings in same column including a memory cell of the plurality of memory cell to be programmed, applies a second voltage to an unselected bit line connected to at least two memory strings in same column including a memory cell of the plurality of memory cell to be program-prohibited, applies a third voltage to a selected string selection line connected to at least two memory strings in same row, applies a fourth voltage to an unselected string selection line connected to at least two memory strings in same row, and applies a program operation voltage to a plurality of word lines, each word line connected to each corresponding memory cell in the memory string, wherein the first to third voltages are positive voltages.