A novel sol–gel process has been successfully developed for preparing strontium bismuth tantalite (SrBi2Ta2O9, known as SBT) with ethylene alcohol as a solvent and acetic acid as a catalyst. The size of phase-pure SBT nanoparticles could be 4 nm in diameter by avoiding the formation of the fluorite phase at the low temperatures (550–600◦C). The behavior of the crystallization in SBT is investigated by XRD, TG-DTA, FT-IR and TEM. The nanoparticle size as a function of the annealing temperature is also investigated. By fitting the Arrhenius curve, we obtain the crystalline and vitreous growth activation energies, i.e, Ea1 = 0.709 eV and Ea2 = 0.093 eV. The two other fitting parameters, transition temperature T0 = 814 K (541◦C) and transition width △= 0.022, directly show the behavior of the phase transition from vitreous phase to crystalline phase.