Abstract: Two key-problems,angle measurement and angle prediction, of the swift target acquisition in array radar are studied. Firstly, from the respect of required beam arrangement, discrimination feature and the performance of angle measurement, the two algorithms named amplitude-comparison monopulse-like algorithm and average weighted with amplitude algorithm, for measuring the target-s angle with array radars are studied. The method for nonlinear adjustment when the average weighted with amplitude algorithm is applied is posed. Then, the algorithms for predicting the target-s angle with tracking filters are analysed. A simple decoupled filter named SDF is presented. At last, these algorithms are tested in a simulation system for array radar.