Abstract: Due to the influence of fault characteristics such as weak feed and impedance change of inverter-interfaced renewable energy source (IIRES), malfunctions may occur in directional element when the positive sequence voltage or memory voltage is utilized as polarization voltages. In order to solve this problem, a fault direction criterion based on the correlation of positive sequence reactive current waveform is proposed in this paper. According to the difference of positive sequence dynamic reactive current between IIRES and synchronous generator during fault, the fault direction is determined by calculating the correlation coefficient between measurement waveform and reference waveform of dynamic reactive current. If the forward fault occurs at the IIRES side, the reactive power current measurement waveform and reference waveform are almost the same. If the reverse fault occurs at the IIRES side, the reactive power current measurement waveform and reference waveform are different. The simulation results indicate that the proposed directional element can reliably and sensitively determine the fault direction under different fault conditions.