Abstract: A novel fault location method to identify the single-phase earth fault occurred in the neutral non-effectual grounded system is presented. It is a practical improvement which presents the method for determining the adaptive correlation coefficient threshold. This study focuses on the synchronization of signal processing, the improvement of the correlation coefficient and the threshold; widen the criterion gap between the fault section and the healthy fault section. Large amounts of ATP simulations show that the fault location algorithm based on adaptive correlation analysis can accurately determine fault points when applied to the neutral non-effectual grounded system.