Abstract: The existing performance speculations of adaptive array have some shortcomings like sensitivity of weight scaling or the difficulty of reflecting the successive processing performance. To deal with this problem, a new speculation was proposed, i.e., signal-to-interference-noise ratio (SINR) gain, for evaluating the anti-jamming performance of adaptive array. Besides, the analytic expression of SINR gain was also derived for uniformly linear spaced array. The proposed SINR gain shows a clear physical meaning and can compare the anti-jamming performance for different anti-jamming spatial filters. Furthermore, the successive performance can be directly obtained via the proposed SINR gain. Finally, the results of numerical experiments show the effectiveness of the proposed method.