PURPOSE: A specific water-absorbing resin and antistatic polymer are selected and added to improve both of the properties, water-absorption and antistatic property, synergetically and give the fiber having both of satisfactory properties by adding a small amount of them.

CONSTITUTION: A water-absorbing resin of less than 0.5 micron particle size in absolute dry and of 10W300cc/g water absorption and an antistatic polymer of an acrylonitrile copolymer containing 30W85wt% copolymer coponents of formulaIor II are added by less than 10wt%, preferably 1.5W8wt%, to give a composition containig more than 90wt% acrylonitrile polymer. The resultant composition is subjected to wet spinning to form fiber that has pores of more than 0.2 micron major axis in the cross section, less than 10 seconds of charge half-life measured at 20°C and 65% HR and more than 20% water retention. The amounts of the water-absorbing resin and the antistatic polymer are 0.5W 7.0wt% and 1.0W7.5wt% respectively. The water-absorbing polymer is preferably a copolymer of acrylonitrile containing less than 30% crosslinking monomers such as acrylic diester and other vinyl monomers.