Abstract: Effect of quantity, performance and flexibility of air-to-air missile on airfight effectiveness was analyzed, and effective manner to use air-to-air missile in air action was discussed to improve fighter’s survivability and its airfight effectiveness. Three degrees of freedom particle kinetic equations were employed to model the missile’s motion, and typical trace of missile was partitioned into three different phases: breaking, parting, and contacting. Meanwhile, the different requirements of the missile trace were given in each phase; the characteristics of the missile radar cross section(RCS)were also taken into account in the simulation analysis. One-one airfight pattern was used to simulate a Mirage2000 vs. a F16 under circumstances of high altitude middle distance, different amounts of air-to-air missiles, various opportunities to launch missile, et al. Results show that fighter’s velocity, disengagement angle and missile’s velocity significantly affect the operational effectiveness of fighter.