The kinetics of chromium(VI) oxidations of iota- and lambda-carrageenans biopolymers have been investigated in aqueous perchlorate solutions at a constant ionic strength of 4.0 mol dm-3 and a temperature of 35 oC. The progress of the reactions was followed spectrophotometrically. The reactions showed a first-order dependence in [CrVI] and fractional-second order kinetics with respect to the concentrations of carrageenans. The influence of hydrogen ion concentration on the oxidation rates showed that the oxidation processes were acidcatalyzed. Increasing ionic strength of the reactions decreased the rates. Kinetic evidence for the formation of 1:2 complexes between chromium(VI) and carrageenans were revealed. The activation parameters of the rate constants along with thermodynamic parameters of the equilibrium constants were computed and discussed. A plausible oxidation mechanism consistent with the kinetic results has been suggested. An isokinetic relationship for some redox reactions involving chromium(VI) as an oxidant was examined. The tendency for formation of coordination polymer complexes between the formed biopolymer precursor chelating agents and some metal cations was investigated.