Abstract: To address the sensitivity of the performance of multiple-input multiple-output (MIMO) dual-function radar communication (DFRC) systems to the accuracy of channel state information (CSI), we formulate the problem of hybrid analog and digital beamforming under imperfect CSI conditions and propose a robust hybrid beamformer design method. Specifically, by utilizing the prior statistical information of the CSI uncertainties, the expected transmit digital and analog beamforming matrices are obtained via minimizing the weighted mean square error of radar power pattern subject to the constraints on the communication outage probability. The formulated non-convex problem is initially approximated using Cantelli’s Inequality, followed by the application of the alternating direction method of multipliers (ADMM) to obtain the solution. Numerical simulations are performed to compare the performance of the proposed method with other algorithms, demonstrating the effectiveness and robustness of the proposed MIMO-DFRC hybrid beamforming design.