Nearby metamaterial (MM) slabs can interact with each other, resulting strong coupling which eventually change the characteristics of an individual MM slab. In this study, we apply the signal flow graph technique to examine the coupling phenomenon between MM slabs. To this end, we use the scattering (S-) parameters of each individual MM slab as well as the whole composite MM structure in which MM slabs are cascaded to one another. Different from other techniques available in the literature, our proposed technique gives not only qualitative information about the presence of the coupling but also quantitative data about the level of coupling via S-parameters of the coupling. We investigated S-parameters of a MM slab composed of split-ring-resonators especially designed for resonance within X-band (8.2–12.4 GHz).