Containers have a crucial role in determining the porosity of packed spheres. The new gravitational sphere packing method is applied for loose packed particles based on Monte-Carlo simulation. The model is simulated in a cylindrical container by considering the effect of the wall. A new method is employed to examine the porosity of spheres in the inner part of the cylinder without the effect of boundaries, where spheres can be packed in different rectangular containers to show the structure of packing within sides of different sizes. (C) 2012 Elsevier B.V. All rights reserved.