The photoluminescence spectrum of poly(ethylene terephthalate) (PET) excited by light with wavdength in the reign from 260 to 360 nm was investigated．When the excitation wavelength was shorter than 300 nm

it was observed that the profile and structure of the photoluminescence spectrum of PET did not change with the increase of the excitation wavelength．When the excitation wavelength was longer than 300 nm

the wavelength dependence of the spectrumwas observed．Excited in the reign from 300 nm to the value that was a little larger than the maximum excitation wavelength

there was only one main peak at 367 nm in the photoluminescenee spectrum．However

with the continued increasing of the excitation wavelength

another peak appeared at 387 nm and its intensity increased accompanying with the decrease of the intensity of the peak at 367nm．At last

the peak at 387 nm became the main peak andthe peakat 367 nm changedtothe second main peak．It was suggested that the photofuminescence of 367 nm and 387 nm would rather come from the excimeric emission and the ground state dimmer

respectively

than origin from the same emitting center.