Abstract: A loudspeaker diaphragm is provided as an injection molded material including 50 to 80 weight % of a matrix resin of polyolefins and 20 to 50 weight % of flaky mica having an average aspect ratio of more than 10 and including at least 3 weight % or more of pearl mica. The matrix resin of polyolefins includes respective flakes of the flaky mica orientated in parallel to thereby improve the acoustic characteristics and concurrently the design appearance of the diaphragm. The design appearance of the diaphragm can have bright colors and a pearly luster.