Abstract: Based on the dwell-time approach and Gronwall-Bellman's inequality,a new approach to input-to-state stability and optimal control problems for a class of switched systems is presented.Under the condition that input-to-state of switched system is stable,the constraint conditions on switching instants and switched number are transformed into linear form.A new form of objective function is constructed for switched system optimal problem.Compared with the existing methods,the proposed method does not employ new variables and construct input-to-state control Lyapunov function,and input-to-state stability properties are not required for all subsystems.It provides convenience to controller optimal design.Simulation results are provided to demonstrate the feasibility of the proposed method in the paper.