Abstract: Beam-space high resolution algorithm for direction finding of wide-band sources is discussed in this paper. Based on the wide-band beam-forming technique, called constant beam-width beam-forming, we present the wide-band model of the direction finding problem, and introduce some conclusions of narrow band processing to wide-band processing. Further more, we prove the relation between beams and the threshold for resolving multi-sources. The simulation results show the beam-space algorithm has good performance.