A 3D stacked semiconductor structure is provided, comprising a plurality of stacks vertically formed on a substrate and disposed parallel to each other, a dielectric layer formed on the stacks, a plurality of conductive plugs independently formed in the dielectric layer; and a metal-oxide-semiconductor (MOS) layer formed on the dielectric layer. One of the stacks at least comprises a plurality of multi-layered pillars, and each of the multi-layered pillars comprises a plurality of insulating layers and a plurality of semiconductor layers arranged alternately. The MOS layer comprises a plurality of MOS structures connected to the conductive plugs respectively, and function as layer-selectors for selecting and decoding the to-be-operated layer.