ZnO wurtzite nonoparticles (crystallite sizes ca. 15 nm) were prepared via thermal decomposition of batch supercritical antisolvent (SAS) processed zinc acetate precursor. Batch SAS could produce nanoscale zinc acetate particles (average sizes ca. 35 nm at 4 degrees C and 15 MPa when choosing the optimum now of the supercritical fluid, ZnO nanoparticles were formed by decomposing nanoparticles of zinc acetate at 150, 300 and 450 degrees C, respectively. The Zinc acetate and ZnO nanoparticles were characterized based on TEM, FTIR spectroscopy and X-ray powder diffraction. TGA and FTIR spectra were used to the thermal decomposition course of the zinc acetate particles. ZnO nanoparticles were ultrapure and have no residual organic group. Calcination temperatures of zinc acetate particles have no significantly negative Influence on the size of final ZnO particle. The ZnO crystalline agglomeration, particle size and size distribution are determined by the quality of the SAS processed precursors, The present work is helpful to develop a clean, size controllable nanoparticle preparation method.