Abstract: A polyvinyl alcohol-degrading enzyme producing strain of a Janthinobacterium sp.,which can use polyvinyl alcohol as sole carbon source,was isolated from Daihai.Morphological characteristics and 16S rDNA verifies that it belongs to Janthinobacterium sp.The crude enzyme solution degrading polyvinyl alcohol(PVA)was extracted from the fermentation broth of the strain.The enzymatic properties of the extracted enzyme were analyzed,and their distribution and suitable environmental condition were studied.The results showed that PVA-degrading enzyme was distributed both inside and outside the cell,with most being secreted outside the cell.The optimum reaction conditions of the enzyme were:PVA 1.0 g/L,pH 6.5,temperature 45℃.The enzymatic activity at pH 6.5,35℃was relatively stable.The crude enzyme presented PVA degradation rates above 82%after 10 h of reaction.