A series of polyesters consisting of aromatic main-chain backbones and flexible aliphatic side chains with 4-cyanobiphenyl end groups has been synthesized on the basis of the polycondensation of 2,2＇-bis(trifluoromethyl)-4,4＇-biphenyldicarbonyl chloride with 2,2＇-bis{omega-[4-(4-cyanophenyl)phenyoxy]-n-alkoxycarbonyl]}-4,4＇-biphenyldiol (PEFBP). As recently reported, for a PEFBP polyester containing eleven methylene units in the side chains, PEFBP(n=11), four different structures have been identified in addition to the isotropic melt. They are as follows : an orthorhombic crystalline phase (K-O), two triclinic crystalline phases (K-T1 and K-T2) in the high-temperature region, and a nematic phase (N). To further understand the phase transformation mechanisms involved, in this publication, overall phase transformation kinetics have been carried out using isothermal differential scanning calorimety (DSC) experiments. Special attention has been given to the temperature regions where three phases (K-O, K-T1, and K-T2) exist. It is found that each phase possesses its own transformation rates. Three overall transformation rate regions are observed that are separated at temperatures of 95 and 113 degrees C, which serve as rate boundaries between these different phases. For the linear growth rates measured by polarized light microscopy (PLM), the growth rate of the K-O phase is difficult to be detected due to its fast transformation rates. The linear growth rates of the K-T1 and K-T2 phases can, however, be measured. Although these rate regions generally correspond to the overall transformation rates obtained from DSC, a rate minimum can be observed at 130 degrees C in the linear growth rate data of the K-T2 phase above 113 degrees C. This minimum is formed due to the introduction of a new linear growth rate branch above 130 degrees C. The morphological studies under PLM, transmission electron microscopy, and the melting temperature changes using DSC indicate that these two growth rate branches in the K-T2 phase correspond to two kinds of morphological developments : folded chain spherulites and extended chain single crystals. Furthermore, the linear growth rates are affected more by this morphological change compared to the overall transformation rates.