Dielectric relaxation measurements of methyl cellulose with substituted phenols p-cresol, m-cresol and o-cresol mixture in different non-polar solvents CCl4, benzene and 1,4-dioxan for different concentrations over the frequency range of 10 MHz-20 GHz at 303 K have been carried out using Time Domain Reflectometry (TDR). Dielectric parameters such as static permittivity (ε0) and relaxation time (τ) were determined and discussed to yield information on the molecular structure and dynamics of the mixture. The dielectric constant and relaxation time were found to be high for methyl cellulose with p-cresol in CCl4 compared with the other mixtures. © 2009 Elsevier B.V. All rights reserved.