In this paper,we first extend the classical Hé1ein's convergence theorem to a sequence of rescaled branched conformal immersions.By virtue of this local convergence theorem,we study the blow-up behavior of a sequence of branched conformal immersions of a closed Riemann surface in Rn with uniformly bounded areas and Willmore energies.Furthermore,we prove that the integral identity of Gauss curvature is true.