Abstract: With AC impedance method used, the rational parameters of electrical conductivity of NdF3-LiF-Nd2O3 system melts measured by Continuously Varying Cell Constant (CVCC) technique was determined. It was deemed that the Z′ value in CVCC formula should be selected as the sum of the resistances of melt and both electrode and conductor by fitting on the Nyquist diagram. And reading the real part of the total circuit impedance at high frequency was also a rational selection. Then, the electrical conductivity of NdF3-LiF-Nd2O3 system melts was investigated experimentally to get the linear regression equation of the conductivity in relation to temperature and melt composition, i.e., k(S·cm^-1)=-2.111+0.005323 t(°C)+0.03220 wLiF (%)-0.1026 wNd2O3(%). Analyzing the equation, a conclusion is drawn that the electrical conductivity of the melts increases with temperature and LiF mass fraction, but decreases with increasing Nd2O3 mass fraction.