This paper deals with the problem of adaptive control of uncertain nonlinear port-controlled Hamiltonian systems subject to actuator saturation, and proposes a number of results on the control design. Firstly, an adaptive H∞ control design approach is presented by using both the dissipative Hamiltonian structural and saturated actuator properties for the case that there are both parametric uncertainties and external disturbances in the AS systems. Secondly, the results obtained for Hamiltonian systems are applied to adaptive control for a class of uncertain nonlinear affine systems subject to actuator saturation, and several interesting results are obtained. Finally, study of an example of power systems with simulations shows that the adaptive controller proposed in this paper is effective.