In this paper we prove the gradient structure of solutions for a nonautonomous cascade system defined on Banach spaces, where the x–variable evolves independently via \(\dot{x} = Ax+f(t,x)\) and influences the y–variable through \(\dot{y} = By+g(x,y)\) . By first analyzing the long–time dynamics of the nonautonomous x–equation and then examining the resulting y–dynamics for each asymptotic state of x, we provide a complete description of the system’s gradient structure in two levels: a more abstract and general, with less hypotheses on f, and a deeper level of description, when the term f(t, x) is asymptotically autonomous. Finally, we present a description when the term f(t, x) is a small nonautonomous perturbation of an autonomous term.