In this paper we studied the molecular mechanism of the cold crystallization upon heating quenched Poly(ethylene terephthalate) (PET). From morphological observations we found spherulites in the samples annealed at lower temperature although it was deduced in early papers that cold crystallization occurs in the form of fringed micellar structure. The cold crystallization kinetics of PET was also examined by the dilatometric method. The dependence of the Avrami exponent on the thermal history indicated that the int…