A 3D memory device is provided. The 3D memory device includes a first logic base layer, a second layer, and a third layer. The first logic base layer comprises a first type DEMUX, a plurality of second type DEMUXs coupled to the first type DEMUX, a first type MUX, and a plurality of second type MUXs coupled to the first type MUX. The second layer comprises a first group of memory units. Each of the first group of memory units is respectively coupled to a corresponding DEMUX of the plurality of second type DEMUXs and a corresponding MUX of the plurality of second type MUXs. The third layer comprises a second group of memory units. Each of the second group of memory units is respectively coupled to a corresponding DEMUX of the plurality of second type DEMUXs and a corresponding MUX of the plurality of second type MUXs.