The effect of temperature on the orientation of pigment in PSⅡwas studied by the fluorescence excitation spectra and polarization fluorescence spectra of spinach thylakoid solution. The experimental results showed that in the temperature range of 15～45 ℃ the absorption band of chl a at 436 nm at room temperature red-shifted with increasing temperature. The excitation spectra intensity reached the maximum at the temperature of 35 ℃, but greatly reduced with temperature at 65 and 78 ℃. In the polarization fluorescence spectra the fluorescence peak of PSⅡ didn’t change with temperature from 15 to 45 ℃. It was also found that the calculated fluorescence polarization degree increased with the temperature in the entire temperature range. The analysis indicated that temperature would affect the orientation of the pigments in PSII and the coupling strength between pigments so to change photosynthetic efficiency. The results will give a certain reference for the study of the energy absorption and transmission, regulation mechanism and also on solar cell materials.