Beach erosion of the Hitotsumatsu beach on the Kujukuri coast in Chiba Prefecture facing the Pacific Ocean was investigated by field observations in 1997 and 1998. The Kujukuri coast has been formed by the deposition of sediment supplied from the sea cliffs located both ends of a 60km long stretch of coastline. Disappearance of sand source of the sea cliff due to the construction of wave dissipating works on foot of sea cliff as a measure against erosion and obstruction of continuous sand movement by breakwaters of the harbors caused severe beach erosion on the downcoast. Here such a situation is studied and future measures against beach erosion is discussed.