Abstract: To clarify the resistance induction effect of β-aminobutyric acid(BABA)against tobacco black shank disease caused by Phytophthora parasitica, the disease investigation was carried out for tobacco treated by BABA, the physiological and biochemical indexes and expression levels of resistance related genes were detected. The results showed that: 1)BABA induced hypersensitive response(HR) and increased the expression of HIN1 gene which was related to HR in tobacco. 2)BABA promoted the activities of peroxidase(POD), polyphenol oxidase(PPO)and catalase(CAT). When tobacco was not inoculated with P. parasitica, BABA not only induced a significant increase of O₂^- content by 142.2%, but also caused the accumulation of malondialdehyde(MDA). After tobacco was inoculated with P. parasitica, BABA reduced the expression level of NtrbohD which was involved in the production of reactive oxygen by 56.9%. 3)The treatment of 5 mmol/L BABA had a resistance induction effect for tobacco against black shank disease, and the control effect was 56.3% after the treatment.