The variation of alpha track density at age of 45 days of plantation of radish plant is listed in Table 2. The alpha track densities in leaves of the radish plant also increased with the age of plant. Since the uranium and radium present in the soil and then transfer to plant have very long half life. With age of plants the radionuclide contents were continuously accumulated in the different parts of plants. Thus, the alpha track densities in radish plant after 45 days are higher than that of 30 days.