The temperature dependence of the dielectric properties of k- and i-carragueean aqueous solutions with various counterion species, K, Ca, and Na, were investigated over the frequency range 10 2 -10 6 Hz and the temperature range 2.0-80.0 °C. In the case of κ-carrageenan solutions, just below the coil-to-helix transition temperature, T CH , the de conductivity sharply decreases within a few degrees of temperature. In contrast, the sharp decrease was not observed for i-carrageenan solutions. The dielectric relaxation process with the relaxation time ∼100 μs, which can be assigned to the counterion fluctuation in the parallel direction to the helical axis, arises below T CH . Just below T CH , the relaxation strength increases sharply with decreasing temperature for both the carrageenan type with all the counterion species exhibiting the coil-to-helix transition, reaching 10 3 at the temperatures far below T CH . These findings indicate that the counterions are tightly bound to helical molecules due to an increase of the charge density along the helical axis during the coil-helix transition. The relaxation time reflecting the fluctuation distance increases sharply in the initial stage of gelation and gradually reaches a constant value. We think that the formation of the high charge density region, which is connected with the aggregated region of helices, is determined by which process, a growth of the length of the helices or the aggregation of the helices, precedes in the initial stage of gelation.