The habitat of a rare minnow Tanichthys albonubes in Conghua town, Guangdong province was investigated form June 2005 to December 2005, and water quality, sediment and plankton were quantified. The water quality of the habitat was better in June and December than in other months. Total nitrogen in water bodies was high in August, and high concentration of total nitrogen and total phosphorus appeared in October. The COD was high in all months. The contents of nitrogen and organism in sediment were high, however, the contents of phosphorus was low. The max density of phytoplankton and zooplankton in water bodies appeared in August. In other months the quantity and species were low. There were fewer species but larger quantity in both of Cyanophyta and Chlorophyta than diatoms.