As part of this study the intertidal sediment of the Sakarun beach on the Dugi Otok Island has been analysed. Sakarun beach is a very popular tourist destination of the Dugi Otok Island. Since the eastern coast of the Adriatic Sea is dominantly built of karstified carbonate rocks, sandy beaches are not very common. Sand population of the Sakarun beach is declining which may cause general loss of beach. To prevent further sediment loss and protect the beach from extinction, the origin of the sediment of Sakarun beach was determined as a part of this work. The intertidal sediment along three beach profiles has been analysed. Granulometric analysis showed that beach is composed of moderately well sorted sand and moderately well sorted slightly gravelly sand. The sand is mostly composed of carbonate component, while siliciclastic component is present in traces. X-ray diffraction showed the mineral composition where calcite and magnesium calcite are dominant, while aragonite, quartz and halite occur in smaller amount. The sediment is analysed under the microscope. Analysis showed that sand is mostly composed of fragmented organism shells. Carbonate component analysis showed that sand from Sakarun beach contains an extremely high percentage of the carbonate minerals, which is a typical characteristic of the sediment that deposits near shores and islands. By knowing the characteristics and sediment origin, we are getting a clearer picture of beach regulations and their preservations, sediment budget and its input and output.