Abstract: The methods of disturbance, spiral cylindrical cavity and stripline resonator were used respectively for measuring the permittivities for microwave dielectric substrates. The substrates are made from PTFE based fine ceramics, and errors of measurement have been analyzed. The cause for improving dielectric properties by rolling may be explained by SEM(Scanning Electron Microscope) observation. The effect of different surface treatment on peel strength of substrate has been investigated.