Abstract: A new method of equivalent circuit parameters identification method of induction motor using nameplate data is presented. An motor equivalent circuit including stray-load loss is built by introducing an equivalent stray-load loss resistor; then, an optimization model of parameter identification is developed by using parameters computed in the equivalent circuit and nameplate data. In experiment, the model is solved by using particle swarm optimization(PSO), and the effective search range is confirmed. Experimental results demonstrate the proposed method can identifies motor equivalent circuit parameters effectively.