  Employing extended phase space formalism, we study critical phenomenon of
A-charge and C-charge for holographic theories dual to Gauss-Bonnet black
holes. We find a universal critical Gauss-Bonnet coupling, giving rise to a
universal ratio between the two central charges at the critical point. This
leads to a new intepretation for critical behavior of Gauss-Bonnet black holes
in terms of the boundary degrees of freedoms, although the solutions are
electrically neutral. Another novel feature is for either of the central
charges, the transition temperature is beyond the critical point but is upper
bounded by causality of the boundary theories.
