To better understand the salinity effect on the compaction behaviour of soil, standard Proctor compactiontest was conducted on soil samples with different salinities. Matric suction and small-strain shearmodulus,Gmax, were determined and pore size distribution was also investigated on samples staticallycompacted at different water contents. Results showed that with the decrease of soil salinity from initialvalue of 2.1&(g of salt/kg of dry soil) to zero, the maximum dry density increased and the optimumwater content decreased, whereas there was no significant change with the increase of soil salinity from2.1&to 6.76&. Interestingly, it was observed thatGmaxalso decreased when the soil salinity decreasedfrom initial value of 2.1&to zero and kept almost constant when the soil salinity increased from 2.1&to6.76&, for dry samples with similar matric suction and also for samples compacted at optimum state andon wet side whose matric suctions were slightly different due to the difference in remoulded watercontent. Furthermore, the effect of salinity on compaction behaviour andGmaxdecreased for samplescompacted from dry side to wet side. The pore size distribution exhibited bi-modal characteristics withtwo populations of micro- and macro-pores not only for samples compacted on dry side and at optimumstate, but also for those compacted on wet side. Further examination showed that the modal size ofmicro-pores shifted to lower values and that of macro-pores shifted to higher values for saline soilcompared to the soil without salt.