The alginate degrading bacteria have been screened from the marine environment. Sodium alginate and NaCl were required for cell growth and enzyme production of 145-C strain and the adequate concentrations were 0.7 and 2.5%, respectively. The effective nitrogen source was peptone and adequate temperature was 28$pm$2$^{circ}C$. The 145-C strain was identified as Vibrio sp. from biochemical and biological experiment. The extracellular enzyme produced by Vibrio sp. was purified and the molecular weight was estimated to be 27, 000.