This article deals with the stability analysis and the derivation of ISS-Lyapunov functions for infinitedimensional linear systems subject to saturations. Two cases are considered: 1) the saturation acts in the same space as the control space; 2) the saturation acts in another space, especially a Banach space. For the first case, an explicit ISS-Lyapunov function can be derived. For the second case, we prove the global asymptotic stability of the origin when considering all weak solutions.