Flexible multistage rotor systems that are supported by water-lubricated rubber bearings (WLRBs) are seen in various engineering applications. Vibration analysis is important to design and performance of such dynamic systems. In the past, due to the lack of reliable models of WLRBs, vibration analysis of this type of rotor systems has not been well addressed. In this paper, a method for modeling and analysis of WLRB-supported multistage rotor systems is proposed. In the development, a new model of WLRBs is integrated with a distributed transfer function formulation, which eventually yields accurate results on the eigensolutions, critical speeds, and steady-state responses of WLRB-supported rotor systems. The proposed method is illustrated in a numerical study on a three-stage rotor system. It is shown that the proposed method provides a useful tool for optimal design of flexible multistage rotor systems with WLRBs.