P2X7 is the most important subtype of the ATP receptors known so far.  Recent investigations showed that the downstream signaling pathway of P2X7 is coupled with several key inflammatory molecules including IL-1β and IL-18, this suggests P2X7 might have roles in the inflammatory diseases.  Moreover, attenuation of P2X7 by selective antagonists in vitro and knockout mice in vivo reducing the inflammatory response indicated that P2X7 is a potential therapeutic target for inflammatory diseases.  However, most previous studies on P2X7 were focused on nerve system diseases most, while its effects in inflammatory respiratory diseases, especially in asthma, chronic obstructive pulmonary disease (COPD) and lung cancer have been poorly investigated.  In this paper, we reviewed the research progress on the structure, distribution, biological activities of P2X7 and its relationship with inflammatory respiratory diseases including asthma, COPD and lung cancer, along with the development of P2X7 antagonist as therapeutics.