A mixed H2/H∞ performance criterion with common Lyapunov matrix is proposed for polynomial fuzzy systems.Sufficient conditions for the existence of mixed H2/H∞ state feedback fuzzy controller are derived based on the polynomial fuzzy Lyapunov function and Sum-of-Squares (SOS) decomposation technique.The optimal H2/H∞ controller design approach is given by solving a parameter minimization problem with SOS constraints.