The morphological changes of a side-chain liquid-crystalline polymethacrylate during isotropi-zation and liquid-crystallization transitions were studied by means of polarizing microscopy. These tran-sitions were found to be composed of the initiation of a new phase at local places of the old phase matrix andthe growth of the new phase domains. The kinetics of the liquid-crystallization of the polymer from anisotropic melt to a smectic mesophase was also investigated. The isothermal process of the transition can be described by the Avrami equation.The values of the Avrami exponent were found to be around 2.6

which is lower than the value usually obtained for crystallization transition of polymers

but larger than that reported for liquid-crystallization transition of main-chain polymers.These results may indicate the difference in growth geometry of new phase during transition between crystallization and liquid-crystallization in general and between liquid-crystallization of main-chain and side-chain polymers.It was found that the liquid-crystallization of the used side-chain polymethacrylate may occur at small undercoolings with high transformation rate similar to that of main-chain polymers and small-molecule liquid crystals

while the crystallization of polymers can only proceed at large undercoolings.These phenomena can be explained by the idea that the surface free energy of nucleus during liquid-crystallization transition is less than that for crystallization

and evidence was obtained from analysis of the temperature dependence of the transformation rate.