Abstract: In this paper, two principles for designing two-dimensional (2D) multiple-input multiple-output (MIMO) array topology are summarized, which are uniform distribution and less element shadowing for effective aperture. According to these two design principles, a novel 2D MIMO antenna array topology is proposed for UWB short-range high-resolution imaging. Compared with other two different arrays having the same number of transceivers, the proposed array has a better control over the sidelobe level (SL) both in the interference region (IR) and non-interference region (NIR) of the simulated radiation patterns. And for patterns of different focusing distances, the peak sidelobe levels (PSLs) of the proposed array are lower than the compared ones over 2 dB. Experimental imaging results for a distributed target also verify the outstanding imaging capability of the proposed array. Therefore, with a small number of effective elements, the proposed array topology has potential applications for high-efficiency ultra-wideband short-range imaging.