Abstract: A matrix pre-separation method for the determination of uranium content and ²³⁴U/²³⁸U activity ratios in saline waters by ICP-MS and α-spectrometry was studied. The uranium was well pre-separated from saline waters by Chelex-100 resin. The separation efficiency of Na is higher than 99.9%. The recovery of uranium is in the range of 90.5%-106% with s_r<10% (n=4). The ²³⁴U/²³⁸U activity ratios were achieved by α-spectrometry after removing the interferences by P350 resin. The results show that the matrix pre-removal method can be well adapted to determine ²³⁴U/²³⁸U activity ratios in saline waters. The s_r of 3 times determination is less than 5%. The developed method has been already applied to determine the uranium content and ²³⁴U/²³⁸U activity ratios in real saline waters.