Abstract: As a microorganism in the water,photosynthetic bacteria play a key role in water ecology.In order to improve the quality of water by the bacteria in this area,the strain of photosynthetic bacteria was separated from Nanwan resevior.The color of the medium is red in the culture.The physiological and biochemical characteristic were studied and transmission electron micrographs were made.The results showed that the strain of photoynthetic bacteria is Rhodopseudanonas palustris.