A process for producing porous cellulose beads of the present invention is characterized by comprising the steps of: a) mixing an alkali aqueous solution and cellulose to prepare cellulose micro dispersion at low temperature, b) adding water to the cellulose micro dispersion to prepare cellulose slurry, and d) bringing the cellulose slurry into contact with coagulation solvent. A carrier for ligand immobilization of the present invention is characterized by being by shrinking polysaccharide porous beads not less than 10% by a shrinkage rate defined by the following formula, and crosslinking the polysaccharide porous beads: Shrinkage rate (%)=(1−V2/V1)×100 (wherein, V1 indicates the gel volume of polysaccharide porous beads before shrinkage, and V2 indicates the gel volume of polysaccharide porous beads after shrinkage).