Abstarct: Dams are structures that are constructed to regulate water level along the stream of rivers. In this study seepage factors in single-laxyered and multi-laxyered foundations of a dam were investigated experimentally under different conditions. Experiments were carried out on three types of soil, 0.2, 0.6 and 1.2 mm inside the seepage and drainage tank. According to the granulation, single-laxyered, two-laxyered and three -laxyered arrangements were considered and hydraulic potential, hydraulic gradient and seepage discharge parameters were investigated.The results showed that for two-laxyered arrangement with presence of cut off, arrangement of 0.2-1.2 mm had the best performance in control of piping in 490 mm upstream head. For three-laxyered arrangement with cut off, arrangements of 0.2-0.6-1.2 mm and 1.2-0.6-0.2 mm had the best performance in controlling the phenomenon of piping, which for a upstream heads 490 and 480 mm ,respectively. For two-laxyered arrangement without and with cut off, the best performance for controlling the hydraulic gradient were 1.2-0.6 and 0.6-0.2 mm, respectively which for 410 mm upstream head, hydraulic gradient was about 0.0019 and 0.001, respectively. For three -laxyered arrangement without and with cut off, the best performance for controlling the hydraulic gradient were 0.6-0.2-1.2 and 0.2-0.6-1.2 mm, respectively so that for 410 mm upstream head, hydraulic gradient was about 0.0024 and 0.0034, respectively. For two-laxyered arrangement without and with cut off, the best performance in controlling of seepage discharge obtained for arrangements of 0.2-0.6 and 0.6-0.2 mm, respectively. For three-laxyered arrangement without and with cut off, the best performance in controlling of seepage discharge obtained for arrangements of 0.2-1.2-0.6 and 0.2-0.6-1.2 mm, respectively. Investigation of results for single-laxyered and multi-laxyered foundations showed that using multi-laxyered foundations could be considered as an effective alternative in controlling of piping phenomenon, reducing hydraulic gradient and seepage discharge.