Abstract: Forrier transform infrared photoacoustic spectroscopy for untreated and alkali treateddegummed ramie fiber were recorded.It indicated that when the alkali concentrationincreased, the intensity of band near 1430cm^-1 assigned to crystalline region of the fibergraually declined, but that for the band near 898cm^-1 assigned to uncrystalline regiongradually inclined.When the alkali concentration was more than 9.0%(w/w), the area of 898cm^-1 band assigned to CH stretching vibration was near constant.Meanwhile, the alkalitreating temperature (20～80℃) and time (30～120min) appeared almost no influence.

Key words: Fourier transform infrared photoacoustic spectroscopy, degummed ramie, alkali treatment