In this study, the distribution coefficient of Nickel on the Anarak nuclear repository was studied considering the effects of contaminant concentration, soil particle size, and soil/solution ratio. For this purpose, two experiments were designed. The soil sample was collected from inside the trench of the Anarak Nuclear Repository by the channel method and its characteristics was determined using ASTM method. The batch method was employed while different concentration and volume of contaminant solution was added to the soil and was stirred for 24 h at room temperature. The nickel distribution coefficient in the concentration range of 0.05-1 mg/L was determined as 13.63-997.89 mL/g with the mean value of 256.24 mL/g. Adsorption behavior of Nickel in Anarak soil is better followed by Langmuir adsorption isotherm. The results indicated the contrary conversion of Kd with soil particle size and soil/solution ratio. Moreover, the results confirmed the high dependency of Kd on the contaminant concentration.