Pasture ecosystems are currently threatened by various land cover degrading agents such as firing. Researchers throughout the world have attempted to estimate soil erosion rate by different models and approaches. One of the well-known techniques for estimation soil erosion is the use of 137 Cs tracer (with 30.2 year half-time and significant detectable gamma ray) which has been released to troposphere and consequently to soil surface by nuclear tests during 1950-1970. Physical processes along the hill slope such as soil erosion and tillage practices are the most important factors for redistribution of 137 CS. Also, magnetic measures have been identified as the accurate, fast and simple techniques for estimation of soil redistribution in hilly regions. The pastures located in Ferydunshahr district in Isfahan province, central Iran, are intensively fired by improper human activities and subsequently are threatened by severe soil loss. Therefore, the knowledge about the intensity of soil loss is crucial for implementation of conservational practices in the studied area. This study was conducted to evaluate the effects of fire event time on some soil physical, chemical,and magnetic properties and soil erosion rate using 137 Cs technique in a part of pastures in Ferydunshahr district. For this, three pastures which fired partially by human activities in 2001, 2008, and 2011 were selected. In each selected site, two parts of burned and un-burned pastures located on the back slope position, (totally six points) were selected and soil samples were collected from 0-2.5, 2.5-5, 5-10, 10-20 and 20-40 cm. The 137 CS inventory and magnetic susceptibility (at 0.46 and 4.6 kHz) were measured by gamma spectroscopy device and Bartington magnetometer, respectively. Also, some soil chemical and physical properties including organic matter, CaCO 3 , total nitrogen, available potassium, available phosphorus, silt, sand and clay contents and bulk density were measured in all collected samples. The results of this study were interpreted according to fire event time effects on soil physical, chemical and magnetic susceptibility and soil erosion rate using 137 Cs technique. The effect of firing time was evaluated by analysis of variance using factorial statistical design. The results showed that among the soil physical, chemical and magnetic properties, clay content had the highest correlation ( r =0.87) with 137 Cs inventory in all samples. Also similar trend was observed between clay contant and 137 Cs ( r =0.94) in unburned sites. Erosion rates were estimated using 137 Cs technique in burned sites by rational and mass balance models,to be 30.87 and 38.91 t ha -1 yr -1 , respectively. Moreover, erosion rates were calculated 18.67 and 23.02 t ha -1 yr -1 for unburned sites using rational and mass balance models, respectively. Statistical analysis showed that there was significant differences ( p 0.05) for soil erosion rate between burned and unburned sites and burned sites showed higher soil erosion compared to unburned sites, Comparison of three selected years from the firing showed that based on the rationale model, soil erosion rates were 17.84, 19.77 and 34.20 t ha -1 yr -1 in 2001, 2008 and 2011, respectively. It is concluded that soil erosion rate has been declined with time after fire events, due to rehabilitation of natural vegetations. In general, soil erosion was higher in burned pastures compared to unburned pastures. Furthermore, existence of high significant relationship between 137 Cs inventory and magnetic susceptibility confirmed the use of magnetic measures as an rapid, inexpensive and simple way to estimate soil redistribution in hilly burned pastures as an alternative for expensive, time and costs consuming 137 Cs technique in the study area. Keywords : Soil redistribution, soil erosion, firing, 137 Cs, magnetic susceptibility