One of the main aspects of physics beyond the standard model is the concept of extra dimensions. Among many extra dimensional cosmological models the so called DGP model (also called brane-induced gravity) with two branches (normal and self accelerating) is of particular interest. In this manuscript we consider the normal branch of the DGP model by assuming agegraphic dark energy (ADE) which is necessary to explain the late time acceleration of the universe. We study this model in a dynamical system approach where is a useful tool in investigating cosmological models. By defining a set of suitable new dimensionless variables, critical points of the system that show two important cosmological epochs and the related eigenvalues will be obtained. Also, we find the effect of extra dimensions in eigenvalues.