The transmission spectrum and conductance of a graphenesuperlattice (GSL) have been studied theoretically by using the adopted transfer matrix method. Heterostructured substrate and series of grounded metallic planes placed over graphene sheet are used to induce periodically modulated Dirac gap and Fermi velocity barrier. As a main result, we found that the number of periods, energy gap and Fermi velocity barrier have considerable effect on transmission probability and conductance of the GSL. Our results reveal tunable transmission and conductance in GSLs which have promising applications in optoelectronic devices such as graphene based filter and switches.