Transmembrane behavior of valinomycin carrying Rb＋ across an erythrocyte membrane was studied through the measurements of Rb＋ content in cell by graphite furnace atomic absorption spectrometry. The influence of several parameters, such as transporting rate and uptake of Rb＋ by the erythrocyte was studied based on the dynamics investigation of the transmembrane process. In addition, the effect of RbCl on the fluorescence intensity of the erythrocyte membrane protein was also examined in this work. The results indicate that the action of valinomycin carrying Rb＋ transporting into the erythrocyte has a kinetic characteristics of series stair reaction. The uptake of Rb＋ by the erythrocyte is mainly controlled by ligand concentration and incubation time. Only high concentration of RbCl can affect the fluorescence intensity of the membrane protein.

Key words: Rb＋, transmembrane behavior, valinomycin, graphite furnace atomic absorption spectrometry, fluorescence