Abstract: For the recent progress in semiconductor, and the development in sensitivity of uncooled infrared imaging device, uncooled IR seeker is applied on the air- to-surface missile, but none of surface-to-air. Because of its short flying time and a nearer distance, uncooled IR seeker is used on Terminal Defence Misslie. Also there are some practical points needing to be researched in deep. There are some key points on the air-to-surface like anti-aircraft. First of all, the different bands it works lead to a different target or background characteristics, affecting the acquired distance; There is a longer integration time constant of uncooled IR detector compared with the cooled, it is hard to track high maneuvering targets; Finally, the aerodynamic heating on the seeker dome will cause severe thermal radiation effect on the detection system in the aerodynamic thermal environment, because of the long-wave IR band and the long time flying. If such problem can be solved favorably, uncooled IR seeker will be applied quickly on Terminal Defence Misslie, and this research will provide a reference.