Infrared precision guided weapons,typified by man portable air defence systems (MANPADS),pose a significant threat to military and civilian aircraft. At present,the most effective countermeasure against heat seeking guided weapon is the directional infrared jamming system,which uses infrared band lasers as the light source. This paper mainly introduces how Raytheon Company develops a new generation of directed infrared countermeasure system based on the existing AIM 9X seeker technology. The system has many advantages,such as high efficiency,reliability,compactness,light weight and low price,and through the expansion of the functions,it can easily cope with the threat of missiles in various wavelength bands from ultraviolet to mid infrared.