A nonvolatile memory device includes a peripheral circuit region and a memory cell region vertically connected with the peripheral circuit region, the peripheral circuit region including at least one first metal pad, and the memory cell region including at least one second metal pad directly connected with the at least one first metal pad. A method of programming the nonvolatile memory device incudes: receiving a programming command, data for a plurality of pages, and an address corresponding to a selected word-line; programming the data for one of the pages to an unselected word-line; reading data of a previously programmed page from the selected word-line; and programming the data for the remaining pages and the data of the previously programmed page to the selected word-line.