A memory structure including a substrate, stacked structures, at least one isolation structure, a second conductive layer, and a second dielectric layer is provided. The stacked structures are disposed on the substrate. Each of the stacked structures includes a first dielectric layer and a first conductive layer sequentially disposed on the substrate. A first opening is located between two adjacent stacked structures, and the first opening extends into the substrate. The isolation structure is disposed in the first opening and covers a sidewall of the first dielectric layer. The isolation structure has a recess, such that a top profile of the isolation structure is shaped as a funnel. The second conductive layer is disposed on the stacked structures and fills the first opening. The second dielectric layer is disposed between the second conductive layer and the first conductive layer.