A toric manifold is a 2n dimensional compact connected symplectic manifold equipped with an n-dimensional torus acting effectively in a Hamiltonian manner. In 1980s, Delzant completely classified toric manifolds up to equivariant symplectomorphism by their moment images which are convex polytopes. In contrast, a complexity one space is a 2n dimensional compact connected symplectic manifold equipped with an (n-1)-dimensional torus acting effectively in a Hamiltonian manner. Given a toric manifold, by considering the action of an (n-1)-dimensional subtorus, we get a complexity one space. A natural question to ask is: given a complexity one space, is there a way to extend it to a toric manifold? In this talk, I will first talk about complexity one spaces and present the explicit construction of the extension under certain assumptions. Part of the result is joint with Joey Palmer and Sue Tolman.