Abstract: Under a shearing displacement, the membrane experienced three states, defined as an imperfection state, a critical wrinkles state and a macro wrinkles state. The influences of wrinkles in different stages on the free vibration of a membrane were studied and the division principle of the three states was given more clearly. Considering the small bending rigidity of the tension plane membrane, the explicit-to-implicit sequential solution of ANSYS/LS-DYNA was adopted to analyze the dynamic characteristics of the post-buckling tension membrane. According to the analytical results of the ideal membrane, in which the out-plane deformation was ignored, its vibration modes could be divided into two types, through-vibration modes and local vibration modes. Through-vibration modes can be further divided into vertical-through vibration modes and horizontal-through vibration modes. The results show that, in the imperfection state, the effects of wrinkles on free vibration characteristics could be completely negligible. Affected by the distribution of the principal stress, the vertical-through vibration modes appear more easily in low order modes. Its peaks and troughs increase regularly with the increase of order. In the critical-wrinkle state, each frequency fluctuates wildly. The influence of wrinkles begins to be prominent, horizontal-through vibration modes disappear gradually, and the increasing law of vertical through vibration modes is destroyed. In the macro-wrinkle state, each frequency becomes stable. The out-of-plane deformation has great influences on the principal stress and modes.