The albedo factors (number, energy and dose) of the samples with various mean atomic number have been investigated at a scattering angle of 180°. Fourteen different samples in the mean atomic number range 9.743 ≤ Z‾ ≤ 83.00 were obtained with bismuth and cellulose powders by using dilution technique. Thus, albedo factors have been investigated in a wide atomic number range. The samples were irritated by 662 keV gamma rays emitted from aCs radioactive source. The scattered γ -rays were counted by an HPGe detector with active area of 200 mm. It has been observed that albedo factors decrease with increasing mean atomic number. Also, there is a high correlation between albedo factors and mean atomic numbers.