Abstract: Based on the contour features and imaging characteristics of aircraft targets, a method of feature extraction for aircraft target in SAR images based on the variable parametric geometry model is presented. Firstly, a parametric model of aircraft target contour is constructed based on the prior knowledge of aircraft target in this method. Then, the objective function is constructed to measure the fit degree of the target area in the SAR image and model, and solve the optimal parameters by genetic algorithm. Finally, the geometric feature of target is calculated on the basis of the optimal parameter model. Experimental results based on simulated and measured data demonstrate the effectiveness of the proposed method.