Abstract: Biocontrol bacterial NJ-18 was isolated from the soil of oilseed rape field. It was identified as Bacillus subtilis on the basis of morphological, physiological and biochemical characters as well as the sequence analysis of 16S rDNA. The result of the dual-culture test showed that all of the plant pathogens of Sclerotinia sclerotiorum, Rhizoctonia solani, Fusarium moniliforme, Magnaporthe grisea,Fusarium graminearum, Rhizoctonia cerealis, Alternaria solani,Botrytis cinerea and Fusariumoxysporum were inhibited strongly by fermentaion broth of strain NJ-18. And The fermentaion broth of NJ-18 also exhibited protective and curative activity in controlling wheat powdery mildew in potted plant test, with efficacy 96.1% and 88.3%, respectively. 200-fold diluent of the fermentaion broth gave good control efficacy of 58.8% and 51.4% respectively in the protective and curative activity test.