Breakup behavior of system including confined polymeric film between two immiscible layers was studied. Dewetting was found to be responsible for film breakup. Three probable affecting factors on dewetting of three layer system consisting surrounding layer's viscosity, viscosity of confined layer and relative thickness were probed. dewetting dynamic measurements accompanied by surface morphology observations showed that surrounding layer's viscosity is very effective in determining dewetting dynamics because most of the dissipative mechanism occurs in surrounding layers while, viscosity of confined layer doesn’t influence dewetting dynamics significantly and it is negligible. Also relative thickness has considerable effect on dewetting dynamics. Considering these three factors as main decisive factors, empirical equation was presented for our studying case.