Abstract: The problem of target angle measurement in high resolution radar was studied. The principle for measuring angle in mono-pulse radar was introduced, then the model of angle estimation in high resolution radar is built, and the joint probabilistic density function of target angle and return signal was derived.An angle estimation method based on maximum likelihood estimation for high resolution radar was proposed, in which the angle of the target and the return signal were updated iteratively and estimated jointly, and the Cramer Rao Lower Bound of the angle estimation was approximated. The performance of the proposed method was compared against the traditional angle estimation method in narrow band radar by simulation, and it came out that the angle measurement accuracy is higher than traditional method. When the signal-to-noise ratio is given, the more the number of range cell is, the smaller the root mean square of the estimation error is. Simulation results verify that the proposed method is asymptotically unbiased, and has a smaller estimation error variance than traditional method in narrow band radar.