The effect of the electric field on crystallization behaviour of polyamide-6,6 (PA-6,6) was investigated by a rheological measurement. The crystallization kinetics were estimated by monitoring the changes in the absolute value of complex viscosity during crystallization. In both isothermal and nonisothermal crystallization experiments, it is observed that the crystallization rate of PA-6,6 decreases with increasing the applied electrical field. This phenomenon is explained by the orientation of dipole moments in amide groups under the electric field. In the PA-6,6, dipoles of amide groups are aligned antiparallel to each other to yield a stable crystal structure. The external electric field disturbs the antiparallel orientation of dipoles and thus prevents the chain packing during crystallization.