Polyester microfiber fabrics were alcoholyzed at 120, 140, and 160 degrees C in 0.5, 1.0, and 1.5% (w/w) sodium glycerolate/glycerol solutions (NaGR) and the decomposition kinetics was studied in comparison to the hydrolysis done by a 5% aqueous sodium hydroxide solution (NaOH) at temperatures 80, 90, and 100 degrees C. The activation energy and the Arrhenius pre-exponential factor of the alcoholysis found from this study were 30.57 kcal/mol and 2.04 x 10(14)/M s(-1), respectively. In comparison to the hydrolysis case, these values are much higher. The activation energy and the preexponential factor of the hydrolysis found from this study were 14.48 kcal/mol and 1.947 x 10(6)/M s(-1), respectively. The resulting surface morphologies observed by a scanning electron microscope showed that the NaGR-decomposed PET fiber surfaces were distinguished from the NaOH-decomposed PET fiber surfaces by a uniformly developed fine structure of microcraters. It is believed that such a fine microcrater structure of the NaGR-decomposed fiber surface is due to the greater pre-exponential factor as well as to the higher activation energy of the alcoholysis.