Failures like crack and fracture of turbine blades induced by the oncoming flow may occur easily in operation condition.And resonance analyses of a two degree of freedom of turbine blade are given in this paper to discover the mechanism of the interaction between blades as well as air flow which is still not clear.The averaging method is applied to reveal the theoretical characteristics of the forced vibrations of an isolated blade and the quasi-steady flow.The relation between amplitudes and the frequency of blades vibration is given to predict resonance vibrations and chaos behaviours, which is beneficial to aeroelastic designs of the turbomachine.