The Hamo and Hyeopjae beaches in the western part of Jeju Island were studied in terms of seasonal variations of surface sediment and beach profile. Seasonal drift direction of the beach sands also was investigated. The Hamo beach of $7.3^{circ}-10.8^{circ}$ steep is composed of medium sand containing volcanic clasts and shell fragments. The Hyeopjae beach of $2.8^{circ}-6.5^{circ}$ steep is composed of coarse shelly sand. Hamo beach deformation is probably caused by the jetties constructed in the western part of the beach. In the Hyeopjae beach, surface sands were drifted into the dune side by the northwestern stormy wind during winter season.