ABSTRACT. The principal purpose of this paper is to present sufficient conditions for total stability, or stability under constantly acting perturbations, of sets of a sufficiently general kind for nonautonomous ordinary differential equations. To do this, two Liapunov-like functions with specific properties are used. The obtained results include and considerably improve the classical results on total stability of isolated equilibrium points. Applications are presented to study the stability of nonautonomous Lurie-type nonlinear equations. The concept of stability is one of those which reaches beyond the general domain in mathematics. In his well-known dissertation Problème général de la stabilité du mouvement, Liapunov [1] has given several criteria for stability and asymptotic stability of solutions of systems of differential equations with the help of certain auxiliary scalar functions which are now commonly called Liapunov functions. The problem of stability and relationships between stabilities and Liapunov functions has been discussed by many authors since Liapunov.The classical Liapunov theorem on asymptotic stability of the zero solution for a differential equation x = f(t, x) uses a positive definite function V (t, x) whose time derivative V(t, x) along solutions of the differential equation has to be negative definite. However, this stronger property is not always possessed by the natural candidate for the Liapunov function, namely, the energy. The damped harmonic oscillator is the standard example.An effective tool to overcome the difficulty was developed by LaSalle, and is