Abstract: Using the low cadmium (Cd) accumulating tobacco lines RG11 and CF986 and the control high Cd accumulating tobacco line Yuyan5, a hydroponic experiment was carried out to investigate Cd uptake kinetic characteristics of the low Cd accumulating lines. The results showed that:(1) The biomass of the two types of tobacco lines decreased significantly with increasing Cd concentrations in hydroponic solutions(p ≤ 0.05). RG11 and CF986 showed lower biomass decline for both shoots and roots than Yuyan5. Cd accumulation in the two types of tobacco lines increased significantly with increasing Cd concentrations in hydroponic solutions(p ≤ 0.05). Cd concentrations in shoots and roots of RG11 and CF986 were significantly lower than those of Yuyan5 (p ≤ 0.05). (2) The total Cd uptake amount by roots of the two types of tobacco lines increased with increasing Cd treatment time. The slopes of the fitting lines of RG11 and CF986 were 68.6% and 80.0% of Yuyan5. The total Cd uptake amounts by roots of RG11 and CF986 were 8.6% and 27.7% lower than that of Yuyan5 under the same Cd treatment time. (3) Cd uptake rates by roots of the two types of tobacco lines increased with the increasing Cd concentrations in hydroponic solutions. The maximum Cd uptake rates of RG11 and CF986 were 33.4% and 48.5% of Yuyan5. The truly Cd uptake ability of RG11 and CF986 were 51.3% and 7.9% lower than Yuyan5. The slopes of the fitting lines of RG11 and CF986 were 1.3 and 1.4 times higher than Yuyan5. Compared with the high Cd accumulating tobacco line, the low Cd accumulating tobacco lines showed lower Cd uptake ability and greater absorption ability by root apoplasts.