We studied the solar proton differential energy spectra with energy range of 1$\sim$500 MeV at several time intervals during the 2000 July 14 solar flare. The results showed that before flare the spectra could be described by a power law function and after flare the power law spectra still existed above 30 MeV although spectra became softer with time. There was a spectral “knee” occurring at $\sim$30 MeV. We constructed a solar proton differential spectrum from 30 MeV to 3 GeV at peak flux time 10:30 UT and fitted it in the same manner. On the basis of a supposition of having the same power law spectrum in higher energy, we calculated the solar proton integrated fluxes in energy range of from 500 MeV to 20 GeV and compared them with other results obtained from experimental, modeling and theoretical calculations in other big historic SEP events.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html