A new characteristic based on phase space theory to identify magnetizing inrush current is introduced. By reconstructing phase space with chaotic time-series， the one-dimensional single current sampled signal is mapped to a hyper-space to become hyperdimensional; meanwhile， the phase locus indicates the difference between inrush current and inner fault current. Simulation results show that it is possible to reconstruct a similar phase space under variable cases， and the phase locus of inrush current is very different from that of inner fault current.