Flooding phenomena accounts as a serious problem that affects most of watersheds so that the control of this catastrophic phenomena requires reduction of runoff and increasing soil infiltration. Nanotechnology is one of the newest technologies that because of its high potential and unique characteristics, it has extensive applications in all of aspects of science such as natural resources and soil conservation. This study has been done in order to assess the effects of different percentages of Nanozeolite (0.2, 0.4, and 0.6 gram per square meter) on marl soils in several slope degrees (7, 9 and 14 degree) using FEL3 rainfall simulator. The plot was used in this study had 0.5 meter in width, 1 meter in length and 0.4 meter in height. In each of plots 0.3 meter of height was dedicated for draining and the plots were filled with 0.1 meter of marl soil. After adding Nanozeolite to the soil surface, the samples were influenced by 90 millimeters per hour rainfall intensity during 30 minutes. Results showed that all of the Nanozeolite levels (0, 0.2, 0.4 and 0.6) in the three slope angle (7, 9 and 14 degrees) had not significant differences in decreasing runoff in comparison with control treatment.