PURPOSE: To obtain an aqueous dispersion product in dispersibility, generating no hard cake even if preserved for a long period of time and good in re-dispersibility, by containing a fermentation product obtained by culturing petroleum utilizable microorganism in a culture medium containing an org. fine powder, water and carbohydrate as a carbon source.

CONSTITUTION: The composition of an aqueous dispersion is constituted from, on the basis of wt% 0.1W90 org. fine powder, 5W99.9 water and 0.01W10 fermentation product. As the org. fine powder, an insoluble azo pigment, an azo disperse dye or anthraquinone disperse dye is used. As the fermentation product, a fermentation liquid obtained by culturing petroleum utilizable microorganism belonged to a Pseudomonas genus, a Corynebacterium genus, a Nocardia genus, an Arthrobacter genus, a Bacilus genus and an Alkaligenes genus in a culture medium containing carbohydrate as a sole carbon source or the supernatant liquid thereof is used.