Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate, then further oxidized in air, carbonized in nitrogen and activated with carbon dioxide. The effects of carbonization time of PAN hollow fiber precursor on the microstructure, specific surface, pore-size distribution and adsorption properties of PAN-based carbon hollow fiber (PAN-CHF) and PAN-based activated carbon hollow fiber (PAN-ACHF) were studied in this work. After the activation process, the surface area of the PAN-ACHF increased very remarkably, reaches 506 m(2.)g(-1), when fibers are carbonized at 900degreesC for 70 min and activated at 800degreesC for 40 min. The different adsorption ratios to two adsorbates including creatinine and VB12 reflect the number of micropores and mesopores in PAN-ACHF. The dominant pore sizes of mesopores in PAN-ACHF range from 2 to 5 nm. (C) 2005 Springer Science + Business Media, Inc.