PURPOSE: To efficiently produce chitosan particles useful as a metal capturing agent, enzyme immobilizing carrier, drug sustained release carrier, ion exchanger, etc., by dripping an acidic aqueous solution of chitosan into an alkaline aqueous medium.

CONSTITUTION: An acidic aqueous solution of chitosan is dripped into an alkaline aqueous medium, e.g. aqueous solution containing 1W10wt% NaOH, KOH, etc., at a dripping rate to form 10W80 particles per min using a nozzle, having 0.5W2mm inside diameter and the tip separate from the liquid surface, preferably at 1W5cm distance to form solidified particles of chitosan. The above-mentioned acidic aqueous solution of the chitosan is preferably prepared by dissolving the chitosan in 0.2W3% concentration in an aqueous solution of formic acid, propionic acid, etc., normally in 0.2W20% acid concentration to adjust the pH to 1W3. The alkaline aqueous medium may contain an alcohol, e.g. methanol, etc., in an amount of 20W60% based on the total solvent.