Abstract : The object of this project is to determine the concentrations of “uranium” concentration in human blood in 60 selected breast cancer patients (i.e., 30 with cancer and 30 healthy) Babylon Governorate, Iraq. in different ages. By using CR-39, the results indication that the maximum “uranium” concentration in b1ood (2.235ppm) and the minimum concentration (1.034ppm) with the mean uranium concentration in b1ood of patients was (1.7901ppm), while healthy where the maximum value (1.163ppm) The minimum value (0.258ppm) with the mean value (0.7764ppm.). Finally, the uranium concentrations in all samples were below the allowed limit of ICRP and values of other studies.