An aqueous microcapsule suspension liquid exhibiting an excellent (long-term) storage stability and allowing easy re-dispersion and dilution with water even after such a storage, is produced by adding a microorganism-fermented polysaccharide of succinoglycan type as a thickening agent into a microcapsule slurry, or by adding such a microorganism-fermented polysaccharide as a thickening agent to a microcapsule slurry after uniform dilution with water.