The erythrocyte hemolysis was examined to assure Rb + to have a weak toxicity toward human body. The way of Rb + transporting into human erythrocytes was determined, and the factors to affect this transport process were evaluated. The effects of extracellular concentration of Rb + , incubation temperature, incubation time, medium pH, and specific inhibitors were investigated via flame atomic absorption spectrometry. The results indicated that the membrane transport of Rb + through human erythrocytes was controlled mainly by both active transport and simple diffusion. Every mentioned factor took a positive effect on the Rb + uptake by human erythrocytes, however neither DIDS nor nefidpine could inhibit the uptake of Rb + .