The enhancement effect on the fluorescence intensities of an Eu3+ (or/and Sm3+ )-thenoyltrifluoroacetone (TTA )-dibenzo-18-crown-6 (18-C-6 ) system and Eu 3+ (or /and Sm3+ ) -benzoyltrifluoroacetone (BTA )-cetyltrimethylammonium bromide (CTMAB) system by dysprosium has been studied. In the presence of enhancing ions, the fluorescence intensities of the above systems were enhanced by a factor of about 40-150, respectively. The above systems were used for the determination of europlum or/and samarium in rare earths oxides and gave satisfactory results.