In this study, experimental investigation was carried out on the waterproofing performance of waterstop with and without adhesive bonding between concrete and waterstop. During underground structure construction, waterstop is typically used to prevent the water percolating through the joints where consecutive concrete casting is infeasible. For example, waterstop is often adopted at the joint be-tween two panels of diaphragm walls. Conventional waterstop, however, often fails to prevent water per-colation as the waterstop does not fully bond to the concrete, often making water passage through the gap between waterstop and concrete. Artificial adhesive bonding between the waterstop and the concrete was, therefore, applied to improve bonding and reduce water percolation. High water pressure was applied to the two waterstop waterproofing systems, one with adhesive and another without adhesive, and compari-son was made between the two systems.