Abstarct: One of the available double beta decay is that neutrino has an important role and the other double beta decay is . In this thesis, to study the role of neutrino in double beta decay. so that the introduction of decay rules is discussed then double beta decay is studied in both historically and in terms of nuclear and particles structure. In the next section, the methods of double beta decay including shell model, IBM, QRPA, OXBASH computational code used in calculating the transition matrix element are reviewed. Finally, the results of calculations using the described methods and OXBASH computational code are obtained; Thus, the results of experimental tests comparison indicate the efficient OXBASH computational code.