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The open question of crystal symmetry for YBaCuFeO5, still under debate, is resolved by using diffraction anomalous fine structure and resonant multi-beam X-ray diffraction at the Fe and Cu K edges. The different asymmetric intensity distributions observed at 7, 7.1305 and 8.9945 keV give direct evidence that the space group of YBaCuFeO5 should be P4/mmm with the distance between Cu and apical O atoms longer than that between Fe and O atoms. This approach provides a direct way to resolve detailed structural symmetry which is indeterminate in conventional Bragg diffraction.