Abstract: YMnO3 nano-powders were synthesized by microwave-assisted sol-gel method. The composition and the thermo-decomposing process of the gel were studied by means of IR spectrum and TG-DSC analysis. The phase constitutution and particle morphology of the YMnO3 powders were characterized by XRD, FSEM and TEM. The magnetic properties of YMnO3 nano-powders were also studied. The results show that, by using microwave-assisted sol-gel method, nano-sized YMnO3 powders can be synthsized under lower calcined temperature in relatively shorter time compared with the traditional sol-gel method. The YMnO3 powders prepared by the microwave-assisted method have a uniform particle size smaller than 100 nm. The magnetic hysteresis loop result shows that YMnO3 nano-powders exhibit paramagnetic characteristic at room temperature.