A memory structure is provided. The memory structure comprises M array regions and N contact regions. M is an integer ≥2. N is an integer ≥M. Each array region is coupled to at least one contact region. Each contact region comprises a stair structure and a plurality of contacts. The stair structure comprises alternately stacked conductive layers and insulating layers. Each contact is connected to one conductive layer of the stair structure. Two array regions which are adjacent to each other are spatially separated by two contact regions, which are coupled to the two array regions, respectively.