Soil is very important for the production of crops and foodstuffs. One of the most important environmental crisesin the relationship with soil is the phenomenon of soil loss and therefore the soil conservation is very important. In conditions that, there is not the possibility of establishing vegetation, the use of soil conditioners can be useful in controlling soil loss. The present study was conducted with study objevtive of changing soil loss and sediment concentration using soluble montmorillonite nanocaly with rates of 3, 6 and 9 g m-2, and biochar with rate of 160 g m-2 on soil of lomay-sandy. The expriments evaluated under laboratory canditions using rainfall simulation with rainfall intensity of 40 mm h-1 in Tarbiat Modares University. The results showed that the soluble nanocaly with rate of 9 g m-2 and biochar had the more
effects on the variations of soil loss. The soluble nanocaly reduced the surface soil loss, surface sediment concentration, subsurface soil loss and subsurface sediment concentration variables with rates of 89.17, 87.41, 13.64 and 87.31 percent, respectively. Also, biochar could decrese the surface soil loss, surface sediment concentration, subsurface soil loss and subsurface sediment concentration with rates of 85.27, 63.64, 45.20 and 92.88 percent, respectively.