Chitosan (CS) and poly(ethylene glycol) (PEG) composite fibers were prepared via solution spinning. The fibers were then crosslinked with epichlorohydrin (ECH) and glutaraldehyde (GA). Data indicated that the swelling behavior of CS-PEG fibers exhibited pH sensitivity, and crosslinking could change the mechanical properties of fibers. Moreover, the mechano-electro-chemical (MEC) performance showed that the bending direction of fiber specimen would invert at a critical concentration of both of the crosslinking agents. i.e., in a 0.1% HCl aqueous solution under a de electric field, as the ECH concentration was more than 9.0 x 10(-3) M or GA concentration was more than 5.64 x 10(-4) M, the CS-PEG fibers bent to the cathode, while they bent to the anode if ECH or GA concentration was less than the above values respectively. The mechanisms involve variation in the fixed charge density on the macromolecular network as well as difference in the mechanical properties of the fibers. (C) 2000 John Wiley & Sons, Inc.