In this paper, we study the behavior of the theoretical multidimensional resolution limit (TMRL) for two closely spaced targets in the context of MIMO Radar with two scenarios: transmitting array and receiving array are widely spaced and collocated. Particularly, we apply the Stein's lemma which links the Chernoff distance and a given probability of error to derive closed-form expression of the TMRL for these models. The theoretical analysis provides interesting characteristics of the TMRL while numerical simulations show that the TMRL is better when amplitudes of two targets are not identical.