Abstract: Coral sands,one kind of the coral clastic soil,is a special soil with the properties of porosity,weak rigidity and friable.Because coral reefs only exist in tropical skerry and far away from mainland,there are fewer researches about coral reef rock or soil and it is not mentioned in current Chinese standards.Based on real project in Timor-Leste,this paper discusses some engineering behavior of coral sands.Depended on the in-situ test results such as SPT and drilling shear wave velocity test and using the current evaluation methods for engineering properties of quartz sands for reference,the strength properties and seismic liquefaction characteristics of coral sands are discussed.Compare with the quartz sands,coral sands has a lower SPT blow count with higher shear wave velocity, and there is a high risk of liquefaction on coral sands.