Deceptive jamming is a standard technique for an intelligent target to spoof a radar system. Specifically, the target firstly intercepts the transmitted signal of the radar system, and then broadcasts it with a controlled delay. As the broadcasted (deceptive) pulse is usually stronger than the direct reflection extracted by the receiver, an additional false detection will be claimed by the radar system. The false detection can confuse the tracker and results in a waste of weapons for a ground combat system. As a consequence, how to effectively distinguish a deceptive jammer is a meaningful task in modern radar system design. In this paper, we will show that a distributed multiple-input multiple-output (MIMO) radar system can counter the deceptive jamming due to the spatial diversity: a deceptive pulse does not meet the geometric propagation property of a distributed MIMO system, and then one can employ this to detect it. Antijamming capability is a feature of MIMO radar that is unique to it, and seems not to have been previously recognized.