Information modeling for line selection device and section locating device of single-phase earthing-fault is done based on IEC 61850 and object oriented method. The logical nodes of line selection and section locating of earthing-fault based on transient fault signals are defined. Using these logical nodes， the device models for fault line selection and feeder terminal unit（FTU） with fault section locating function are developed. The methods to obtain transient signals of zero sequence voltage and current are analyzed.