Abstract: Objective: Screen chitin-deacetylase-producing strains from marine samples, identify the strain and optimize its fermentation conditions.Methods: Chitin-deacetylase-producing strains were screened by color culture medium from the marine mud of Yanwei Harbor. The strains were identified by morphological, physiological and biochemical characteristics and16 S r DNA sequence analysis. The single factor and orthogonal experimental design were used to optimize the fermentation conditions.Results: Strain MCDA01 producing chitin deacetylase was screened, and it was identified as Acinetobacter schindleri through morphological, biochemical characteristics, and 16 S r DNA sequence analysis. The optimal culture conditions of strain MCDA01 was obtained as follows: 30 ℃, p H8.0, and Na Cl 4%.The optimal fermentation conditions was obtained as follows: the fermentation time was 60 h, the fermentation temperature was 20 ℃, the culture medium starts p H was 7, the liquid loading amount was 20%, and the inducer chitin concentration was 1%. Under this condition, production of enzyme was up to201.37 U/m L, which was increased by 4.14 times. Conclusion: The maximum of enzyme production were optimized to201.37 U/m L, and have industrial application potential.