We evaluate the transmission and the conductance through double and triple non-uniform magnetic barriers in graphene-based nanostructures. The results indicate that non-uniform magnetic modulation results in rich transport properties. Compared with uniform double barrier magnetic structures, both the transmission and the conductance are drastically reduced through non-uniform ones. In the nonuniform triple magnetic barriers, the transmission and the conductance exhibit complicated oscillations, which vary with the width or the height of magnetic barriers. The non-uniformity introduced by altering the height and width of magnetic barriers have different effects on the transmission. For the magnetic barriers with different heights, the transmission is suppressed greatly in both low and high incident wave vector regions, while for the magnetic barriers with different widths, the obvious suppression occurs in the low incident wave vector region. (C) 2010 Published by Elsevier B.V.