In pursuit of energy harvesting from ocean waves, our recent progress on studying wave interaction with a lift-type rotor is discussed in this paper. The particular focus is on the characterization of the rotor's unidirectional responsiveness in waves. The rotor consists of six hydrofoil blades in two sets. One blade set has three blades laid out as a vertical-axis wind turbine of the Darrieus type. The other blade set has three blades configured like a Wells turbine. In combination, the formed rotor can be driven by flows in any direction to perform a unidirectional rotation about its vertically mounted shaft. This unidirectional responsiveness of the rotor also holds in waves, making the rotor an effective device for wave energy conversion. For the parametric study of the rotor, hydrofoil blades using different cross-sectional profiles and chord lengths have been employed to configure the rotor. The rotor was then tested in a wave flume under various wave conditions in a freewheeling mode. Experimental results were analyzed and discussed. The yielded research findings will greatly enhance the fundamental understanding of the rotor performance in waves and effectively guide the prototype rotor development for practical applications.