There are provided a semiconductor memory device and an operating method thereof. The method of operating a semiconductor memory device may include receiving an erase and write (E/W) cycle mode select command and an operation command. The method may include selecting one E/W cycle mode information among a plurality of E/W cycle mode information stored according to the E/W cycle mode select command and storing the selected one E/W cycle mode information. The method may include performing a general operation of a memory cell array according to the one E/W cycle mode information stored and the operation command.