The changes of maximum reflection coefficient, half maximum line breadth and integrated reflection power of double-crystal reflection curves in some planes of the α-LiIO3 single crystal have been investigated under the action of the electrostatic field along the z-axis and x-axis.Based upon the Experimental fact that kB(0) is dependent on the applied voltage and the charging time and there exists a maximun value, a possible explanation is suggested by supposing the displacement and rotation of the IO3- group along and around the z-axis under the action of the electrostatic field.