ZnO nanoparticles and their stable sols were prepared by heating an ethylene glycol solution of Zn(NO₃)₂·6H₂O (0.1 mol/L, 50 mL) with 2 mL of NH₃ aq at 328 K for 24 h. The obtained sol contained ZnO nanoparticles with average diameter of around 20 nm. The particle size decreased with increased the concentration of NH₃. Furthermore, the ZnO nanoparticles dispersed in the sols showed a green photoluminescence peak around 550 nm. The heating procedure of the ethylene glycol solution at 328 K yielded stable sols of ZnO nanoparticles with photoluminescence characteristics. In order to control the photoluminescence characteristics of the ZnO nanoparticles, the ethylene glycol solution which contained zinc nitrate hydrate, glucose, and 1 mol/L of NH₃ aq was heated at 328 K for 24 h. The obtained ZnO nanoparticles dispersed in the sols showed a blue photoluminescence peak at around 420 nm. The glucose reacted with Zn²⁺ ions as a reduction agent. Accordingly, the simple one-pot synthesis process using the heating of the ethylene glycol solution containing zinc nitrate hydrate, NH₃, and glucose achieved control of photoluminescence spectra and enabled the stable dispersion of ZnO nanoparticles.