Abstract: Photosynthetic bacterium strain H3 was isolated from the microbial mat ofa saltern in Hainan Province (China). It is a Gram-negative bacterium. The basterialcells straight or slightly curved rod-shaped, 0.5-0.7μm wide, 1.5-2.5μm long, withmonotrichiate polar flagellum, multiplication by binary fission. In differentenvironmental or culture conditions, pleomorphic cells can be observed. The cellsappear in spherical, ovoid, or club-sphape, sometimes large swellings, spindle orrhombus-shaped cell form, the width and longth may be 4.0 ×7.0μm. Under anaerobicor microaerobic conditions, the culture appears purplish-red with major pigments being Bchl a and carotenoids. The protein contains ca 50% in strain H3 cells. Necessaryamino acids for human and animal were included. Strain H3 grows well in inorganicor organic substrate media containing 0.5-7.0% NaCI. Acetate, alcohol. malonic acid,bicarbonate, paraphenylene diphenol, nitrste, ammonium salt can be used as C or Nsource, VB12 is not required for the growth. The optium conditions for growth are:30℃, PH7-8, 1.0% NaCI concenhation, illumination 1700-2000Lux, under anaerobicor microaerobic. The strain's taxonomic status and applied potential were discussed.