The differences in the structure of polymer chain between the chondroitin-4-sulfate (C4-S) and the chondroitin-6-sulfate (C6-S) are reflected in the intrinsic viscosity values calculated starting from the traditional methods of Huggins, Kraemer, Mead and Fouss, and Martin, and by the method for a single-point determination of intrinsic viscosity [eta]. For the range between 0.4 and 0.5% (w/v) concentrations, we get an agreement in the intrinsic viscosity values. The chains of both polymers present a flexible structure and are not ramified between 0.28 and 1.00% (w/v) concentrations.