Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, temperature and specific interface on the extraction rate were studied. The experimental results showed that the extraction apparent activation energy was 32.0 kJ5mol -1 and the extraction process was controlled by both chemical reaction and diffusion. The extraction rates were measured at different chemical compositions by varying ionic strength, pH value and the concentration of purified Cyanex 923. The initial extraction rate equation was obtained. Solvent extraction kinetics of lanthanum with purified Cyanex 923 in heptane from nitrate medium was investigated by using a constant interfacial cell with laminar flow at 303 K. The effects of stirring speed, temperature and specific interface on the extraction rate were studied. The experimental results showed showed that the extraction apparent activation energy was 32.0 kJ 5 mol -1 and the extraction process was controlled by both chemical reaction and diffusion. The extraction rates were measured at different chemical compositions by varying ionic strength, pH value and the concentration of purified Cyanex 923 The initial extraction rate equation was obtained.