This paper describes a backstepping control for a permanent magnet synchronous generator (PMSG)-based marine current turbine (MCT) dealing with the generator-side converter under faulty conditions. MCT system mainly used PI controllers. However, this type of controllers is very sensitive to faulty conditions such as an open circuit faults in the generator-side converter. In this faulty context, the MCT system power generation and dynamic performances present a high decrease. In order to maintain a minimum of optimal performance, backstepping is therefore investigated for fault-tolerant control purposes.