Abstract: The signal detection model of range-spread target of bistatic multiple-input multiple-output(MIMO) radar is formulated by using the spherically invariant random vectors(SIRV) to describe the non-homogenous clutter. A two-step generalized likelihood ratio test(GLRT) detector algorithm is proposed for detecting the range-spread target. Two different assumptions are made concerning the radar cross section(RCS) coefficient of target: either modeled as deterministic unknown or as Gaussian parameter. Then the GLRT detectors for range-spread target are derived under these two hypotheses. It shows that both detectors lead to the similar results for range-spread target, and the proposed detector enables a detection performance enhancement over that of the point target detectors in the both non-homogenous and Gaussian clutters. Furthermore, the detection performance of both the proposed detectors increases as the virtual aperture number, the target range cell number and the Signal Clutter Ratio (SCR) increase.