Efficient implementation of FIR (finite-impulseresponse) equalizers for wireless channels has attracted much attention these days as equalizations can improve the link performance in hostile mobile radio environment by compensating for inter-symbol interference created by multipath within time dispersive channels. Meanwhile, the MIMO (multiple-input-multiple-output) technique becomes a trend in wireless channel design. On the other hand, we have observed a Least-Squares rational function system identification algorithm, which approximates FIR impulse response with IIR (infiniteimpulse-response) structures effectively. In this paper, we exploit the approximation algorithm and extend the algorithm for a MIMO response approximation which can generate a hardwareefficient MIMO IIR structure for FIR type time domain equalizers in the wireless system. We demonstrate the efficiency and accuracy of our method with MIMO modeling examples.