Abstract: Transport rates of La³⁺,Fe³⁺,Ca³⁺,Na⁺ ions,as well as the amount and selectivity ratio of transport for La³⁺ , Sm³⁺ , and Er³⁺ ions across the liquid membrane by DB-18-C-6 and B-15C-5 were determined.It was found that from a chloride solution the transport rates for Ca²⁺ , La³⁺ , Fe³⁺ and Na⁺ ions are very small. For DB-18-C-6 as carrier, during 12 hrs., the amount of La³⁺ and Na+ ions transported are 49.7% and 54% respectively, and the selectivity ratio for Na⁺/La³⁺ is about 1.08. For B-15-C-5 as carrier the amount of La³⁺ and Na+ ions are 47.5% and 54.0% respectively, and the selectivity ratio for Na⁺/La³⁺ is about 1.13.While for picrate solution the amount of La³⁺ , Sm³⁺ and Er³⁺ions transported are 24.1%, 46.0% and 14% respectively, and the selectivity ratio for Sm³⁺/Er³⁺ , Sm³⁺/La³⁺ and La³⁺/Er³⁺ are 3.28, 1.91 and 1.72 respectively.