Generally, the dielectric properties of biological materials are considered to be frequency variations of the relative permittivity and conductivity. A wide range of interest has been aroused more than a half-century ago. The study of dielectric properties helps to promote the development in fields such as bioelectromagnetics, biochemistry, dosimetry and so on. The study heavily relies on an abundant database under a wide range of frequency spectrum. An attempt has been made to collect as many as measurements on human tissues in-vivo and in-vitro as possible. In this thesis, data from more than fifty human tissues at the frequency range from 100 MHz to 6 GHz are taken into consideration. Besides, alternative mathematical methods are indispensable in exploring and determining the dielectric properties. Take one-pole Debye model for example, as one of the most commonly used mathematical model in Finite Different Time Domain (FDTD) simulation, it is of great importance to identify the influence of each one-pole Debye parameters having on the dielectric properties. For a broader adaptability, simulations are made at a wide spectrum at a interval of 100 MHz. The influence of Debye parameters having on relative permittivity and conductivity is taken into account separately. The main purpose of this thesis is to identify the most influential one-pole Debye parameters among four of them. Based on the results of Debye parameters, further consideration about uncertainty quantification and higher dimensional models application in FDTD simulation could be taken into consideration.