Abstract: The proton flux measurements during several significant solar proton events (SPEs) by the NOAA and GOES satellites are utilized to compare the proton radiation environments in SSO and GEO. Furthermore, the predictions of the proton-induced SEU in the SPEs are calculated by using the two-parameter Bendel model. Generally speaking, the proton-induced SEU has a positive correlation with the total proton flux and the spectrum hardness. The comparison between the proton radiations in SSO and GEO shows that the proton spectrum in SSO is ‘softer’ than that in GEO. For the low-energy protons, the flux in SSO is greater than that in GEO, while the flux in SSO is less than that in GEO for the higher energy protons. The ratio of the upset rates of D424100V (DRAM) and HM6516 (SRAM) in SSO to that in GEO is about 13% to 22%; and the ratio of the upset rate of 93L422 (bipolar) in SSO to that in GEO is about 26% to 57%. By comparing the proton-induced upset rates with the proton radiation in SSO and GEO, it is discovered that each type of the electronic components is sensitive to the protons with different energies.