Abstract: A new method of broadband focusing matrix design for linear array is proposed in this paper. In the method,the array manifold is expanded in the form of sum of an infinite series,which is based on Fourier-Legendre polynomial expansion. The high terms of the series are truncated,and the focusing matrices are banded to ensure that the loss of the focusing is none. The resolution from the new method can be performed without the limitation of the array size and sensors′ interspaces. Furthermore,there is no need to get the preliminary DOA estimations or preset some sectors within which the targets are assumed to lie. The method can be used in the unequally spaced linear arrays process,and has been proved the effectiveness in the sea trials.