Various ground improvement technique have been developed to improve the engineering properties of the weak soils in sites before constructions. Among these techniques is the vibro-stone columns. It can increase the bearing capacity and reduce the foundation settlement. The performance of stone columns depends on soil type, columns depth, area replacement ratio, column material strength, column installation method ... etc. This study is concerned with introducing a simple and relatively cheap technique that can be used as a method for deep foundations besides and piers. This investigation presents the behavior of soft clay soil reinforced with sand columns when tested in oedometer. aseries of modified oedometer tests were carried out on soft clay specimens of 100 mm dia. and 75 mm thick . the soil specimens were reinforced with a 30 mm diameter of compacted moist sand columns of 0 , 15 , 30 , 45 , 60 and 75 mm depth into a prebored hole. the obtained results indicated that the specimens containing sand columns of depth more than 60% of the clay thickness are greatly improved than that without columns . also . soil deformation and consolidation time are decreased progressively with the increase of column depth .