A continuous flow reactor equipped with a low-loss flow channel and a microwave cavity was developed for synthesizing nanophosphors. A continuous solution synthesis of YVO4:Eu,Bi nanophosphor was succeeded through the rapid hydrothermal method using this equipment. Internal quantum efficiency of YVO4:Eu,Bi nanophosphor obtained by 20 minutes microwave heating is about 30% at 320 nm as high as that obtained by 6 hours hydrothermal treatment in autoclave.

New HEu$_{1-x}$Gd$_{x}$(MoO$_4$)$_2$ nanophosphors were synthesized by a simple one-step ion-exchange method. These nanophosphors have rod-like particle morphology with 0.5--15,$mu$ m in length and outer diameters in the range of 50--500,nm. By optimization of the composition, the highest emission intensity was obtained for the samples with $x = 0.50$ for both KEu$_{1-x}$Gd$_{x}$(MoO$_{4}$)$_{2}$ and HEu$_{1-x}$Gd$_{x}$(MoO$_{4}$)$_{2}$.