Jia L., Bai J., Guan D., Sun K., Jiao Q., Feng Q. (2016): Extracellular ATP: a potential molecule regulating the defence response of plants to biotic stresses -a review. Plant Protect. Sci., 52: 221-228.Although adenosine 5'-triphosphate (ATP) is commonly considered as an intracellular energy currency molecule, animal, plant, and microbial cells can secrete ATP from the cytosol into the extracellular matrix. In plant cells, extracellular ATP (eATP) is found to play important roles in regulating several physiological processes, such as cell growth, development, and death. Interestingly, recent studies suggest that eATP could be a potential molecule required for the regulation of the defence responses of plants to pathogen infection and herbivore attack. This review article summarises the preliminary studies that have been conducted regarding the possible involvement of eATP in plant defence responses to biotic stress. And, we also attempt to address some speculations and theoretical discussions to aid future research in this area.