This investigation explores the kinetics of the alkaline hydrolysis of regular poly(ethylene terephthalate) (PET) solid fibers and PET micro-porous hollow fibers, using statistical regression analysis. Statistical regression analysis results concerning the kinetics of the alkaline hydrolysis of regular PET solid fibers and PET micro-porous hollow fibers yielded a beta value of 1. The R-2 of the kinetic equation for alpha values from 1.07 to 1.16 exceeded that for alpha = 1. The rate constants of alkaline hydrolysis followed the order PET micro-porous hollow fibers >> regular PET solid fibers. A morphology of large pores of diameter 0.1-3.5 mu m was observed following alkali treatment of the PET micro-porous hollow fibers. The weight loss percentage of the hollow fibers was around 20%. The hollowness of the PET micro-porous hollow fibers after alkali treatment was between 30 and 32%. The PET micro-porous hollow fibers exhibited simultaneous water-absorption/release and keep-warm functions. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1822-1827, 2009