Chemical Vapor Deposition(CVD)is now the main way to prepare diamond(film).After decades of development,from micro-to nano-crystalline diamond films and single crystal diamond with most outstanding properties,applications of diamond(film)continue to grow.Besides industrial and commercial applications,nano-crystalline diamond films in MEMS/NEMS and bio-medical applications draws people's attention.Preparation of large-size single-crystal diamond is the key to promote these applications.This paper analyses characteristics of Microwave Plasma CVD(MPCVD),discusses the problems in commercialization of CVD diamond(film)application,outlooks the future of diamond film applications.