Unconsolidated sand dune is vulnerable to ran-up wave attacks. Adding,recovery of its volume is difficult. To protect the foot of sand dune scarp is important to the crest height conservation. We evaluated effects of the “Sand Dune Scarp Control Works” with an experimental construction. The objects were experienced four typhoon attacks. Beach profile change was caused by beach cusps and mega cusps. We confirmed their effect to protect dune and innocuity to onshore sediment transport.