A semiconductor structure is provided. The semiconductor structure includes a first gate-all-around FET over a substrate, and the first gate-all-around FET includes first nanostructures and a first gate stack surrounding the first nanostructures. The semiconductor structure also includes a first FinFET adjacent to the first gate-all-around FET, and the first FinFET includes a first fin structure and a second gate stack over the first fin structure. The semiconductor structure also includes a gate-cut feature interposing the first gate stack of the first gate-all-around FET and the second gate stack of the first FinFET.