A loudspeaker, comprising a vibration system and a magnetic circuit system cooperating with the vibration system. The vibration system comprises a loudspeaker diaphragm. The loudspeaker diaphragm comprises a thermoplastic polyester elastomer membrane. The loudspeaker diaphragm has an amplitude of vibration of 0.25-1 mm during vibration, and F0 of the loudspeaker is 150-1500 Hz. The loudspeaker has the characteristic of good listening effect.