A 3-D FDTD method for full anisotropic medium was formulated and examined. Contrary to other methods, this approach is separated into two parts: dielectric properties parts and wave marching parts. Dielectric anisotropic properties are realized through the relationships of electric properties---electric flux versus electric field and magnetic properties---magnetic flux versus magnetic field. EM wave marching is realized through the relationships of magnetic field versus electric flux and electric field versus magnetic flux. For the reason that medium properties are expressed separately, this method can avoid major modifications of core updating equations if the studied medium properties change. This can reduces the time necessary for making new FDTD programs for mediums with other properties. This is the reason that this method can also be extended to dispersive, anisotropic & dispersive mediums. A simplified perfect matched layer (PML) was modified and used as the absorbing boundary condition to match anisotropic medium.