Cubic phase ZrO2-8% （in mole）Y2O3, nano-powders were prepared in basic media by the microwave-hydrothermal method, with Zr（OH）4 and Y（OH）3 co-precipitated from ZrO（NO3）2·2H2O and Y（NO3）3·6H2O solutions as the precursors. The resultant precipitates were characterized by X-ray diffraction, transmission electron microscopy and inductively coupled plasma-optima emission spectrometry. Influents of solution content, temperature and time on the crystalline type and morphology of yttrium stabilized cubic zirconia were studied. Well dispersed and narrowly distributed ZrO2 -8%Y2O3, nanopowders with particle sizes of 5-10 nm were obtained under the given process conditions. The best conditions for the microwave-hydrothermal method are as follows： reaction time of 20-40 min, precursor content of 0.2 mol/l, temperature of 194-200℃ , and KOH content of 0.4 mol/l . The product purity is 99% in mass.