Hard X-ray and extremely low energy bulk-sensitive photoelectron spectroscopy has been performed in the temperature range of 100-330K for Fe3O4. In the high temperature phase just above the Verwey transition, the intensity at the Fermi level (E-F) is still very weak, but it increases gradually with further increasing the temperature (250 K, 330 K) in consistence with the temperature dependence of the conductivity. The spectral behaviors near E-F with temperature are well explained by the polaronic model, which shows the change from small polaron to large polaron.