The infrared spectra of polyoxometalates are addressed. The vibration frequencies of some synthesized polyoxometalates in recent years are emphasized. It was found that the infrared spectra of polyoxometalates result from stretch vibration frequency of the metal-oxygen, and 1 100-400 cm(-1) is the region of the characteristic absorption peak. The infrared spectrum contains information about the symmetry of polyoxoanion as well. As an analytical means, the infrared spectrum can be used to distinguish heteropolyanion and provide information on structure.