Abstract: In the elasto-plastic analysis, much more atte'ntion has been paid to bifurcation behaviour of the governing equation which always predicts various mechanism of failure or fractures In reference (5), an infinite plate a thin layer sandwiched was considered for its interface insta bilities and it was shown that the innerbuckling could appear Before the emergence of shear bands.Unfortunately, the analytical derivation of this bifureation is quite tedious about complex function calculus. Hence, the extention of this analytical scheme to the laminated plate will be even difficult and troublesome as we tasted.