Sized-controlled　YVO4　nanoparticles　have　been　synthesized　by　a　simple　microwave　irradiation　processing.　The　products　were　characterized　by　X-ray　diffraction.　transmission　electron　microscopy,　and　ultraviolet-visible　spectroscopy.　The　results　showed　that　the　size　of　as-synthesized　YVO4　powders　was　in　the　range　of　5-18　mm　and　was　extremely　dependent　on　the　Solution　pH　value.　The　optical　measurements　displayed　the　obvious　quantum-size　effect　of　the　products.　(C)　2004　Elsevier　Ltd.　All　rights　reserved.