Polarizability acts as an essential property in the design of novel materials. It is of great significance to obtain the dynamic polarizability over terahertz frequencies for substance containing complex intermolecular interactions. The experimental access of the polarizability is based on the accurate determination of its intrinsic dielectric constant. Meanwhile, thecoherent detection scheme of terahertz time-domain spectroscopy (THz-TDS) makes it an ideal alternative for dielectric constants measurements. However, most organic crystalline materials occupy strong absorption features over terahertz frequencies, and samples for THz characterization are commonly prepared by homogeneously dispersing the analyte within the THz transparent polymer matrix. The application of the dilution matrix makes the dielectric constants of mixture samples measured by the THz-TDS cannot be directly utilized to calculate the polarizability. We proposed in this work a ternary model based on the Landau, Lifshitz and Looyenga (LLL) theory to extract the intrinsic dielectric constants of analyte by removing the dielectric contribution of trapped air and polymer background. The extracted intrinsic dielectric constants can be further used to calculate polarizability combining with the Clausius-Mossotti equation. The proposed methodology is exemplified in detail with the polarizability determination of crystalline salicylic acid (SA) embedded in twopolymer matrixpolyethylene (PE) and polytetrafluoroethylene (PTFE), respectively. Mixture pellets at three concentrations are designed for THz-TDS measurement for each polymer matrix. The application of the proposed method on the original dielectric spectra of mixture pellets provides intrinsic dielectric constants and polarizability values of salicylic acid with promising consistency. The results reported in this work also represent the first experimentally measured polarizability values for crystalline salicylic acid, which is (17.2±0.2) and (17.6±1.0) 3 for analyte embedded in PE and PTFE respectively.