An aeroelastic model of a ducted rotor is developed and applied in the investigation of the dynamics of the ducted rotor in forward flight. The studies focus on the rotor vibrations of a fully ducted rotor as well as a duct rotor with a front opening. The results indicate that while the ducted rotor with a front opening can significantly reduce the adverse duct pitching moment, it can also increase hub vibration in forward flight due to the inflow changes, the blade tip-loss effect and rotor edgewise flow speed changes. Other parametric studies such as the blade stiffness and the rotor cyclic pitch controls are also conducted. It is shown that the blade flap stiffness is an important design parameter for the rotor without cyclic pitch controls. The model developed in this study can be refined based on future testing data, and it can also be applied in the preliminary studies of the ducted rotor performance, design and flight control.