Plant fungal diseases are the main factor that affects agricultural production. In order to inhibit fungus diseases, the flat confrontation experiment and the molecular detection were employed for the isolation of biocontrol bacteria. Bacillus L103 was isolated from a vegetable field in suburb of Beijing. The antimicrobial spectrum suggests that this strain shows a high level of inhibitory activity against the tested plant pathogenic fungi. The analysis of 16S rDNA and housekeeping gene sequence shows that it is a kind of Bacillus megaterium. It could produce β-1,4-glucanase, that was detected on CMC-Na plates and congo red staining. We amplified the endo-β-1,4-glucanase gene and sequenced it according to GenBank No.HM130670.1. Its full length was found to be 1482bp and its amino acid number is about 494. Its endo-β-1,4-glucanase gene sequence has 92％ homology with that of the endo-β-1,4-glucanase gene of Bacillus sp. HB102, and 85% homology with that of Bacillus subtilis.