Abstract: To improve the robustness of parameters on-line identification strategy of dual three phase induction motor, and supply accurate machine parameters to control system, this paper introduces a novel method of on-line identifying the stator resistance and leakage inductance of dual three phase induction motor. According to the machine mathematical model in harmonic subspace, the voltage vector injection in this space causes a clockwise rotated current vector, meanwhile can also keeps reference voltage in fundamental subspace unchanged and without bringing the torque and flux oscillation. The stator resistance and leakage can be calculated by the injected voltage vector and sampled stator currents. The principle of the parameters on-line identification and voltage vector injection strategy which can also keep the amplitude and phase of the generated currents in harmonic space under control is presented and analyzed in detail. Experimental results proved the feasibility and validity of proposed method.