The Heusler alloy Ni2MnGa with ferromagnetic shape memory effect has the development potential. It has attracted much attention in the research of new intelligent materials. In this paper, the research progresses of the tetragonal distortions, phonon softening, magnetic properties and other aspects in Ni2MnGa alloys which were calculated by first-principles method are summarized; at the same time, discuss the site preference of Ni, Ti, Co doping elements in Ni2MnGa alloy and the influences of the doping elements on the electronic structure, martensitic transformation temperature TM and the Curie temperature TC.