Strain XW-1 producing extracellular cellulose was isolated from 80 cm depth under the surface layer at Zoige Plateau Alpine Wetland. It was identified as a Brevundimonas sp. by its morphological, the physiological and biochemical properties and 16S rDNA sequence analysis. The results of cellulose producing research showed that the optimum carbon sourse was 0.5% CMC-Na, the optimum temperature was 20°C. Under this condition, the highest cellulose activity reached to 15.6 U/mL in the third day. Enzymatic properties showed that the optimum pH value is 6.0 and the optimum reaction temperature is 20°C, the relative enzyme activity reach to 80% at 15°C, moreover, at 5°C the relative enzyme activity still reach to 56%.