The local structures around Ce and Gd atoms in Ce1-xGdxO2-x/2 (x = 0-0.30) were studied by means of extended X-ray absorption fine structure (EXAFS) spectrometry. Oxygen vacancies introduced by doping trivalent Gd ion to CeO2 were seen to be located around both Gd and Ce ions. The association of two Ga ions and one oxygen vacancy is proposed in heavily doped solid solutions, supporting the decrease in the ionic conductivity in the heavily doped region previously reported.