To understand the effect of the montmorillonite (MMT) particles on the crystallization kinetics and crystalline morphology of nylon 6 upon nano-composite formation, we have characterized the crystallization behaviors by using light scattering, wide-angle X-ray diffraction (WAXD), transmission electron microscope (TEM) and theological measurement. The correlation between the nucleating effect and the growth mechanism of the different polymorphism (gamma-phase) of nylon 6 in the nano-composite (N6C3.7) was probed. N6C3.7 exhibited gamma-phase crystal due to the nucleating effect of the dispersed MMT particles into the nylon 6 matrix throughout the whole T-c range (=150-215 degrees C). The lamellar growth of the gamma-phase crystal took place on both sides of the dispersed MMT particles. In comparison between the temperature dependence of the characteristic relaxation time and the crystallization time, the lamellar growth of the gamma-phase crystal has been discussed. The stable growth of the gamma-phase was strongly disturbed at low T-c range (=160-190 degrees C) due to the lack of time for crystallization. (C) 2009 Elsevier Ltd. All rights reserved.