Abstract: Reticulated vitreous carbon (RVC) is used as an adsorbent for cesium in this work. The influence of adsorption time and temperature on the distribution ratio of cesium between RVC and liquid sodium is investigated in the static condition by using neutron activation analysis(NAA). The results show that the distribution ratio of cesium is higher than 10 when the temperature is in the range of 200~400 ℃, and the adsorption lasts longer than 40 h. These results provide an experimental basis for installation and operation of cesium-adsorption device in the by-pass sodium loop for determination of radio active cesium.