Dielectric measurements of nylon-6 & nylon-11 with substituted phenols p-cresol, m-cresol and o-cresol mixture in different concentrations over the frequency range from 10 MHz- 20 GHz was carried out using the Time Domain Reflectometry (TDR). By least square fit method, the dielectric parameters such as static dielectric constant (ε0), dielectric constant at high frequency (ε∞) and relaxation time (τ) were extracted from complex permittivity spectra at temperature range from 40°C to 15°C. Here we are discussing the temperature effect on these binary mixtures.