Bacterial strain CAB-1 was isolated according to its chitinolytic activity and antifungal activities against plant pathogens including Botrytis cinerea in virto. Strain CAB-1 was identified as Bacillus atrophaeus based on the biochemical characters, sequences analysis of 16S rDNA and gyrB. Through sequence analysis and function predicting based on it whole genome, two chitinase genes were located and cloned from strain CAB-1. These two cloned chitinase genes were ligated into the prokaryotic expression vector and fusion proteins were induced. Chitinase activities of the induced protein Chit1 and Chit2 were testified by plate transparent circle method. In the meantime, only Chit1 protein showed antifungal activity against B. cinerea. The expression condition of Chit1 protein was optimized. The results showed that incubating at 30℃ for 24 hours in shaker and induced by IPTG of 0.2 mmol/L to 1.0 mmol/L was recognized as the optimized condition for Chit1 protein production.