Water, soil and plants sources are concentrators of radioactivity and constitute a good indicator for radioactive contamination in the arid environment. There were few data for radioactivity in arid, semi-natural ecosystem. Radioactivity of soil, water and plant in the eastern arid border of Iran was unknown. This has been measured in sources of plant, soil and water as samples for assessment of radioactivity. The results showed that the mean radioactivity in plant is 772±95 Bq per kg dry plant, in soil is 268±50 Bq per kg dry soil and in water is 216±31 Bq per liter waste. Therefore, radioactivity concentration of ionizing radiation in plants is more than water and soil sources in eastern arid border of Iran, Sistan and Blouchestan province.