Abstract: In this paper, influence of azimuth non-uniform sampling on SAR systems with multiple-receive apertures in azimuth is derived theoretically. The analysis shows that several ghosting peaks are presented around the main peak, and at the same time non-uniform sampling will cause peak gain loss and the broadening to the main beam. Formulas to calculate the Peek-to-Ghost-Ratio (PGR) and peak gain loss are given, which show that they are related to the degree of non-uniform and the azimuth oversampling ratio quantitatively. The correctness of these formulas is validated further by simulation experiments.