The unperturbed dimensions of macromolecules have been measured by GPC coupled with a capillary viscometer. Polymer were fractionated by GPC column. The capillary automatic viscometer determines the intrinsic viscosity of the fraction. Using calibration and/or universal calibration

the molecular weight is obtained. In a number of theoretical equations

the unperturbed parameter

Zθ is obtained from the intercept of the plot off intrinsic viscosity and molecular weight.The results agree well with the corresponding values measured from the convention-al method and GPC coupled with a Low=Angle laser Light-Scattering Photometer.