A simple method for measuring the optical non-homogeneity and growth layers in t he LiNbO3∶Fe crystal is reported. We can compute the change of refra ctive ind ex Δne at different positions in the crystal according to the distan ce be tween e—o light-spots, which vary with the change of the position of incident l ight-spot in crystal. Furthermore we can obtain the non-homogeneity and determin e the position and thickness of the growth layers in the crystal.