This paper presents a coaxial resonator technique applied for the measurement of the permittivity of ferroelectric thick film. A 1/4-wavelength coaxial resonator with appropriate dimensions were designed and made for measurements so that there is only TEM fundamental resonance in the interest frequency range. The permittivity may be extracted from the measured TEM fundamental resonant frequency in the resonator. The equivalent capacitance to the part between sample and open end of coaxial line is discussed, in which the boundary element numerical method was used for modeling the capacitance. The resonant frequency was measured using network analyzer and good experimental results were obtained.