A non-volatile memory device, which includes a plurality of memory transistors that are coupled with a plurality of bit lines and a plurality of word lines, and methods of operating a non-volatile memory device are provided. A selected bit line for programming and unselected bit lines for preventing programming are determined from the plurality of bit lines. An inhibiting voltage is applied to at least one inhibiting word line chosen from the plurality of word lines. The at least one inhibiting word line includes a word line positioned closest to a string selection line. A programming voltage is applied to a selected word line chosen from the plurality of word lines. Data is programmed into a memory transistor coupled with the selected word line and the selected bit line while preventing data from being programming into memory transistors coupled with the unselected bit line.