  In this paper, we study the quasinormal modes(QNMs) of massless scalar
perturbations to probe the Van der Waals like small and large black
holes(SBH/LBH) phase transition of (charged) AdS black holes in the
4-dimensional Einstein Gauss-Bonnet gravity. We find that the signature of this
SBH/LBH phase transition in the isobaric process can be detected since the
slopes of the QNMs frequencies change drastically different in small and large
black holes near the critical point. The obtained results further support that
the QNMs can be a dynamic probe of the thermodynamic properties in black holes.
