The effects of sintering aids addition on the microstructures and microwave dielectric properties of NdAlO 3 ceramics were investigated. V 2 O 5 was selected as liquid phase sintering aid to lower the sintering temperature of NdAlO 3 ceramics. With V 2 O 5 addition, the densification temperature of NdAlO 3 can be effectively reduced from 1650 °C to 1390∼1410 °C. The crystalline phase exhibited no phase differences at low addition level while Nd 4 Al 2 O 9 and NdAl 11 O 18 present as second phases as the addition level was over 1 wt.%. The quality factor Q×f was strongly dependent upon the amount of additions. Q×f values of 64,000 GHz and 48,000 GHz could be obtained at 1390∼1410 °C with 0.25 wt.% and 0.5 wt.% V 2 O 5 addition, respectively. During all addition ranges, the relative dielectric constants were not significantly different and ranged from 21.6 to 22.5.The temperature coefficients varies from –31∼–43 ppm/°C.