Electrorheological elastomer (ERE) is a member of smart material family. Many efforts have been made to develop high-performance EREs for preparing active electrorheological (ER) particles. In this work, an excellent ER particles named spherical tetragonal BaTiO3 were successfully synthesized by hydrothermal method at different conditions using Ba(OH)(2)center dot 8H(2)O and amorphous TiO2 as original materials. Analysis of the structure and morphology of the synthesized particles with Raman, XRD, SEM techniques indicates that the additives play a crucial role in determining the surface morphology of the particles. Additionally, we discovered that the spherical tetragonal BaTiO3 particles with different surface morphology possess different tetragonality, surface hydrophilicity and dielectric property, and thus exhibit distinct electric-field response. The response of the BaTiO3 particles to electric-field is in the order of daisy-shaped >walnut-shaped >sphere particles. Further experiments reveal that high tetragonality, fine dielectric performance and super surface hydrophilicity of BaTiO3 particles are the major power in boosting their electric-field response. (C) 2015 Elsevier B.V. All rights reserved.