To get line-of-sight angular rate in a target tracking system, a method of measuring LOS angular rate based on image sequences, obtained by a single imaging detector, was introduced in this paper. With the sequence images, body LOS angles were obtained by the moving target image coordinates, missile attitude angles were got by images matching, and the LOS angular rate was calculated with these two variables. Experimental results show the idea is practical. Combining with the image tracking algorithm, the body LOS angle can be obtained in real time. Missile attitude angles are obtained well by the images matching, with the attitude transform error less than ±5%. And the LOS angular rate can be better restored using Kalman filter, with body LOS angle and missile attitude angle containing noise. The method has a practical value, for being applicable to micro-aircraft′s guidance and detection, eliminating gyro inertial elements, and reducing the weight of detecting devices.