Abstract: To clarify the characteristics of absorption, accumulation and chemical speciation of cadmium (Cd) in tobacco, the Cd absorption characteristics in tobacco, the contents and chemical speciation of Cd in tobacco roots, stalks and leaves at different Cd concentrations were studied by hydroponic experiments. The results showed that the amount of Cd absorption in tobacco decreased first then increased with the proceeding of Cd treatment; it became stable at 240 μg·plant^-1 then decreased after that. The Cd absorption rate of tobacco presented a tendency of increase-decrease-increase and peaked within 4-5 hours after tobacco plants were transplanted in Cd solutions. With the increase of Cd concentration, the accumulation of dry matter in tobacco increased first and then decreased, and the dry matter weight was raised at a low Cd concentration. At different Cd concentrations, Cd content was the highest in stalks and the lowest in leaves, and it increased in all parts of tobacco with the increase of Cd concentration. The Cd in roots was mainly deionized water-extractable Cd, followed by acetic acid-extractable Cd, the Cd in leaves mainly existed in the form of binding to acetic acid.With the increase of Cd concentration, the Cd chemical speciation transformed from low activities in tobacco into the chemical speciation with high activities.