Energy resources of offshore wind and ocean wave are clean, renewable and abundant. Various technologies have been developed to utilize the two kinds of energy separately. This paper presents the principle of an integrated generation unit for offshore wind power and ocean wave energy. The principle of the unit includes that: The wind rotor with retractable blades and the 3-DOF (degrees of freedom) mechanism with the hemispherical oscillating body are used to collect the irregular wind and wave power, respectively; The energy conversion devices (ECDs) are utilized to convert mechanical energy from both the wind rotor and the 3-DOF mechanism into hydraulic energy; The hydraulic energy is used to drive the hydraulic motors and electrical generators to produce electricity. Some analyses and experiments of the unit is conducted.