The prevention of the torsional and bending vibrations resonance is the main design problem of the wind power plant with vertical rotation axis. The torsion vibrations analysis is especially difficult for two – coherent cross – section blade of wind rotor with vertical axis, and planetary rotation of blades.The presented determination method of the wind turbines torque, power and angular speed enables the assessment of forced vibrations frequency and consequently for the mast proper design. Keywords: steel structures; wind power plants; torsion vibrations.