Abstract: This paper introduces an analyzing method and principle of beamforming with acoustic lenses,and analyses a design method of cylindrical acoustic lenses.An acoustic lens system is designed by ZEMAX and made by ABS,and tests of several parameters have been completed in a cistern.The lens system achieves an angular resolution of 1deg.at 500 kHz with a 20deg.field of vision.Experimental result shows that the lens system satisfies the demand of design in beam width,sidelobe levels and field of vision,and it well verifies the focusing properties of cylindrical acoustic lenses.