Abstract: An acoustical metastructure is proposed to focus reflected wave into multiple focus in a broad band. This metastructure has a simple configuration and planar shape, consisting of an array of groove-like metamaterial units with subwavelength width. The method of harnessing the convergence of reflected wave by controlling the local phase response is proposed. An analytical expression of the parameter distribution for realizing broadband focusing at given loci is derived, which can be used to precisely design the acoustic metastructure capable with broadband multi-focus focusing. The performance of the designed metastructure is demonstrated via numerical simulations, showing that the metastructure is able to converge the acoustic energy of incident wave into the preset multiple focus. This scheme enables free and precise control of the number and relative locations of loci, and can be designed to yield desired focusing effect even in the presence of obstacles with sizes comparable to the working wavelength. With the merits of simple fabrication and tunable focus, our design may be applicable to many important situations such as medical ultrasound and non-destructive tests