Abstract: With the influence of salient pole and saturation of the rotor, self-inductance and mutual inductance of permanent magnet synchronous motor（PMSM） winding exhibit periodic changes along rotor position. On the basis of analyzing the variation of line inductance with angle, two initial position calculation methods were proposed, using the fundamental component and the second harmonic component of the line inductance. Neither method requires an additional rotor polarity identification process. The fundamental and second harmonic components of the winding inductance can be calculated and extracted by injecting six equal-width voltage pulses into the windings. In order to fully verify the effectiveness of the proposed methods, three typical permanent magnet synchronous motors were selected for test verification and result analysis. The results show that both methods can calculate the initial rotor position and determine the magnetic poles reliably and effectively.