Abstract: Some scholars suggest that we use autoregressive (AR) model solve the problem that the conventional inverse beam-forming (IBF) is unable to break through the Rayleigh limit, and improve the bear resolution for inverse beam-forming, but the detection performance of this method (AR_IBF) is worse in the practical application. A modified method (MAR_IBF) is advanced for AR_IBF by modifying the AR in this paper, and which has good detection performance and bear resolution. Theory analysis and numerical simulation show that the detection performance of MAR_IBF is improved near 10logN ( N being number of elements), compared to the detection performance of AR_IBF.