A method of temperature-modulated differential scanning calorimetry (TMDSC), proposed by Toda et al., is used to study the crystallization kinetics of a polyester-imid, namely poly(4,4＇-phthaloimidobenzoyldodecamethyoxycarbonyl). The polymer shows one irreversible melting/crystallization transition and one smaller, partially reversible transition. The experimental results prove that with this method one can obtain an important parameter that characterizes polymer crystallization via the temperature-dependence of the crystal-growth rate. The TMDSC data consist of the total heat flow, the magnitude of the apparent heat capacity, and the change of the phase lag of the heat how in the transition region. No specific assumptions an made about the crystallization kinetics. (C) 2000 Elsevier Science Ltd. All rights reserved.