Dielectric properties of two mixtures of normal primary alcohols were investigated at 20°C in a frequency range of 10 MHz to 250 MHz. The complex dielectric coefficients of Heptyl-Decyl and Octyl-Nonyl alcohol mixtures containing various percentages of the constituents have been determined by two graphical methods. In the first chapters general theoretical as well as experimental descriptions are given. Presentation and interpretation of the data are discussed in the final chapters.