Abstract: Direction finding sensitivities (DFSs) analysis is an integral part of the high-performance radar system design and calibration of various parameters. Based on the first-order sensitivity analysis of MUSIC algorithm to system errors (SEs) which causes differences between the array manifold used by MUSIC and the true array manifold, the direction finding sensitivity for colocated MIMO radar is investigated. The performance of direction finding in the presence of phase, gain or location errors of the element in transmitting and receiving array and the effect of virtual extend ability for MIMO radar with respect to system errors is further analyzed and tested by simulation. Additionally, for a given arbitrary antenna geometry, the formulas of DFSs and MSEs for MIMO radar using MUSIC algorithm are developed for relatively small SEs. And the formula for computing the ambiguity thresholds of the MUSIC algorithm as a function of target separation and other DF system parame ters are derived for relatively large SEs. The presented analysis methods and related conclusions could be as the complement of MIMO radar system analysis and design.