Abstract: Recently, it has been shown by Kapustin and Tomasiello that the conditions that Tolman and the speaker used to define Hamiltonian action on generalized K\"ahler manifolds are exactly the conditions in physics for general (2,2) gauged sigma models. In this talk, I would like to discuss the equivariant cohomology theory for Hamiltonian actions on generalized complex manifolds. In particular, we would discuss Kirwan injectivity theorem and Duistermaat-heckman formular for the push-forward measure in the context of generalized complex geometry.