Two kinds of superlattice reflections from oxygenated YBaCo4O7+delta phase are investigated based on the electron diffraction. In light of the method of the Niggli reduced cell, corresponding superstructures are determined to be a hexagonal lattice with parameters of a(A) = 10.90(4) angstrom and c(A) = 10.02(6) angstrom and an orthorhombic lattice with parameters of a(B) = 18.90(4) angstrom, b(B) = 10.90(5) angstrom and c(B) = 10.05(0)angstrom, respectively. With respect to their respective parent hexagonal structure, the two superstructures are determined to be root 3 x root 3 x 1 structure and 3 x root 3 x 1 structure. In addition, the origin of superlattice reflections is also discussed. The study advances our understanding of structural property, the extraordinary oxygen ordering and the oxygen diffusion process in YBaCo4O7+delta. (C) 2011 Elsevier B.V. All rights reserved.