In this study, the water desalination across Si-passivated nanopores graphene has been investigated by using molecular dynamic simulation. The effect of pore size, membrane curvature, and applied pressure on water flow rate is explored. It is shown that the salt ions rejection can be affected by membrane cur- vature. Furthermore, it is shown that in the pore vicinity, the oxygen density distribution is symmetrical and asymmetrical for the fixed and unfixed membranes, respectively. Finally, it is examined that the shapes of density surface can play an important role in the salt ion rejection.