Luminescent phosphors GdVO₄: Eu³⁺ was prepared in solutions with different pH values by hydrothermal synthesis route using Gd₂O₃, NH₄VO₃ and Eu₂O₃ as precursors, and cetyl trimethyl ammonium bromide (CTAB) as surfactant. The synthesized products were characterized in terms of morphology, structure and luminescent performance by means of XRD, SEM, TEM, and PL. The results show that in an acid solution with pH=1, the size of synthesized GdVO₄: Eu³⁺ crystal grains is of micron scale; in a solution with pH=4 , their size shrinks to nano-scale; it turned out well-dispersed nano-flakes of about 50 nm in solution with pH=7; besides, in solution with pH=10, a certain amount of impurity Gd(OH)₃ was detected by XRD for the synthesized GdVO₄: Eu³⁺ crystal grains. On the other hand, the surfactant affected obviously the final morphology of the synthesized GdVO₄: Eu³⁺ crystal grains in terms of changes in the crystal growth direction and the aggregation shape, correspondingly, the luminescent properties were affected by grain size and crystallinity. It turned out that square GdVO₄: Eu³⁺ nano-crystals with well crystallinity represented the optimal emission performance. But it is noted that the aggregation effect may weaken the luminescent property of the products.