The wave reflections from several types of open-ended coaxial probes contacted on the various materials have been analyzed precisely by using the finite-difference time-domain(FDTD) technique in this paper. Due to the coordinate transformation from three-dimension to two-dimension, the computation was performed very efficiently. It was found that the reflection from an open-ended coaxial probe reduces as frequency or diameter of a coaxial line increases. The reflections from multi-layered media were also analyzed by the FDTD method. This analysis technique was verified by comparison with measurements and theoretical computations.