The effective atomic numbers and the electron densities of some commonly used solvents, i.e., ethanol, methanol, propanol, butanol, water, toluene, benzene, carbontetrachloride, acetonitrile, chlorobenzene, diethylether, and dioxane at the energies 279, 356, 662, 1173, and 1332 keV were calculated by using the measured mass attenuation coefficients in a well-collimated narrow beam transmission geometry. These values are found to be in good agreement with the theoretical values calculated based on XCOM data.