Fungus strains of Absidia atrospora IFO9471, Gongronella butleri IFO8080 and G. butleri IFO8081 showed rich growth in the supernatants of barley-buckwheat-shochu distillery wastewater (BBS medium) and sweet potato-shochu wastewater (SPS medium). In the SPS medium, the 3 strains grew in a wide pH range and produced larger amounts of chitosan when compared with growth in the BBS medium. G. butleri IFO8081 showed the highest level of chitosan production in the SPS medium and approximately 730 mg/l of chitosan was produced after 5 d culture with pH adjusted to 5.0. Furthermore, 49% of CODMn, 51% of total sugar, 43% of reducing sugar, 45% of protein, 61% of total nitrogen and 88% of total phosphorus in the medium was removed simultaneously with chitosan production.