A marine geological investigation of the glass sand deposit in the beach along the west coast of Ahnmyeon Island, South Chung Cheong Province, Korea was carried out to solve the problen of sand material migration, textural properties of the sands and the glass sand reserve for future exploitation. Several bos coring analyses by means of the internal sedimentary structure.i.e., cross- stratification show significantly that most sands are moving and accumulation along the mean vector direction of $N20^{circ}E-N60^{circ}$ E in the area investigated. The average mean size of the sand sediments in the area studied ranges from 0.212mm to 0.275mm. The mechanism of sand migration in the area is considered to be interplay between longshore drift and flood tidal current. The sorting value of the sands ranges from 0.24 to 0.50. Therefore, these sand sediments are characteristic to be "well sorted". The average chemical composition of the glass sand in the area is the following: $SiO\_2$:-90.8%, $Al_2O_3$: -2.18%, $Fe_2O_3$:-0.73%, CaO:-1.79. The binocular microscope examination of the sands show that most of the sands are characteristically ice- clear quartz in mineral composition and their count percentage is mostly 92% or 96%.