3D hierarchical GdPO4 center dot H2O:Ln(3+) (Ln(3+) = Eu3+, Ce3+, Tb3+) flower clusters were successfully prepared on glass slide substrate by a simple, economical hydrothermal process with the assistance of disodium ethylenediaminetetraacetic acid (Na2H2L, where L-4 = (CH2COO)(2)N(CH2)(2)N(CH2COO)(2)(4)). In this process, Na2H2L was used as both a chelating agent and a structure-director. The hierarchical flower clusters have an average diameter of 7-12 mu m and are composed of well-aligned microrods. The influence of the molar ratio of Na2H2L/Gd3+ and reaction time on the morphology was systematically studied. A possible crystal growth and formation mechanism of hierarchical flower clusters is proposed based on the evolution of morphology as a function of reaction time. The self-assembled GdPO4 center dot H2O:Ln(3+) superstructures exhibit strong orange-red (Eu3+, D-5(0) -> F-7(1)), green (Tb3+, D-5(4) -> F-7(5)) and near ultraviolet emissions (Ce3+, 5d -> F-7(5/2)) under ultraviolet excitation, respectively. This study may provide a new channel for building hierarchically superstructued oxide micro/nanomaterials with optical and new properties. (C) 2017 Elsevier B.V. All rights reserved.